Hybrid cathode for ion plasma deposition systems and methods

Abstract

The invention relates to a mixed cathode for ion plasma deposition systems and methods. A cathode (200) for use in an ion deposition process includes a body (202) defining a working surface (204) of the cathode; and at least one insert (218) coupled to the body. The body comprises a first deposited material, and the at least one insert comprises a second deposited material that is incompatible with the first deposited material. The at least one insert is at least partially exposed at the working cathode surface. The first deposition material and the second deposition material are capable of evaporating in response to an arc generated at the working cathode surface for depositing a coating comprising the first deposition material and the second deposition material on a substrate.

Description

[0001] Federal Research Statement

[0002] The subject matter of this disclosure was made in part under government support pursuant to Contract No. DE-AR0001420 awarded by the Department of Energy (DOE), and the government has certain rights in the subject matter claimed herein. Background of the Disclosure

[0003] The present disclosure generally relates to ion plasma deposition and, more particularly, to cathodes for use in ion plasma deposition systems and methods.

[0004] The ion plasma deposition (IPD) process (also known as cathodic arc deposition or vacuum arc deposition) generally includes placing a cathode in a vacuum environment, providing a substrate or workpiece within the vacuum environment, and inducing a current to the cathode to generate an arc (or cathodic arc) at the working surface of the cathode. After placing the cathode and anode in the vacuum environment and supplying sufficient current to the cathode to create a sufficient potential between the cathode and anode to cause a discharge, a cathodic arc is formed at the working cathode surface. The anode can be the conductive surface of the vacuum chamber or can be a separate structure within the vacuum chamber. The function of the anode is to absorb electrons from the cathode to sustain the discharge. After the arc is formed, it persists for a short period of time, then extinguishes and quickly reforms, giving the illusion of the arc continuously moving over the working cathode surface.

[0005] The cathode is made of a deposition material (e.g., a metal or metal alloy) (e.g., cast, forged, or powder pressed) so as to be included in the coating deposited on the substrate. The cathodic arc erodes or evaporates the deposition material at the working cathode surface. Eroding or evaporating the deposition material from the working cathode surface forms a cloud of coating material in the vacuum environment that contains high-energy ions, charged particles, vapor, and neutral droplets. This coating material can then be used for deposition within the vacuum environment. The coating material can be deposited on a colder surface in the vacuum environment via condensation, and / or deposited on the anode surface due to electrical attraction and condensation. The workpiece provided within the vacuum environment also serves as the surface on which the coating material is deposited. A voltage bias can be applied to the workpiece to influence material deposition by increasing the attraction of ions and charged particles to the surface.

[0006] Costs and material limitations associated with the fabrication and operation of cathodes can significantly limit the IPD process and the ability to deposit relatively complex coating compositions using IPD. For example, cathodes made of compositions or alloys that do not provide suitable strength and / or ductility as solid structures may prematurely break during fabrication or use, which can result in unacceptable yield losses, poor coating quality, and / or no material transfer from the cathode during the IPD process. Thus, the IPD process involving a single cathode is limited with respect to the diversity of compositions that can be practically used to fabricate the cathode and subsequently deposited from the cathode without increasing the likelihood of cathode failure. Depositing coatings with complex compositions may require multiple cathodes, which increases the fabrication and / or equipment costs and complexity.

[0007] Accordingly, there is a need for an IPD cathode that enables a greater diversity and greater flexibility of coating compositions that can be incorporated into and deposited using the cathode, which is beneficial for reducing the process costs associated with the IPD process, allowing the IPD process to be operated for longer periods of time without having to replace the cathode, and / or facilitating the deposition of more uniform and improved coatings on substrates.

[0008] This background section is intended to introduce to the reader various aspects of the field that may be related to various aspects of the present disclosure described and / or claimed below. It is believed that this discussion will assist the reader in providing background information that is beneficial for a better understanding of the various aspects of the present disclosure. Accordingly, these statements should be read from this perspective and not as an admission of prior art. SUMMARY OF THE INVENTION

[0009] In one aspect, a cathode for use in an ion deposition process is provided. The cathode includes a body defining a working surface of the cathode, and the body comprises a first deposition material. The cathode further includes at least one insert coupled to the body. The at least one insert is at least partially exposed at the working cathode surface, and the at least one insert comprises a second deposition material that is incompatible with the first deposition material. The first deposition material and the second deposition material are capable of evaporating in response to an arc generated at the working cathode surface for depositing a coating comprising the first deposition material and the second deposition material on a substrate.

[0010] In another aspect, there is provided an apparatus for depositing a coating on a substrate. The apparatus includes a deposition chamber sized to receive the substrate and a cathode positioned within the deposition chamber. The cathode includes a body defining a working surface of the cathode, and the body contains a first deposition material. The cathode further includes at least one deposition insert coupled to the body. The at least one deposition insert is at least partially exposed at the working cathode surface, and the at least one deposition insert contains a second deposition material that is incompatible with the first deposition material. The apparatus further includes a power supply coupled to the cathode. The power supply is operable to generate an arc at the working cathode surface for evaporating the first deposition material and the second deposition material and depositing the coating including the first deposition material and the second deposition material on the substrate.

[0011] In another aspect, there is provided a method of depositing a coating on a substrate. The method includes: providing a cathode including a body defining a working surface of the cathode, wherein the body contains a first deposition material; coupling at least one insert to the body such that the at least one insert is at least partially exposed at the working cathode surface, wherein the at least one insert contains a second deposition material that is incompatible with the first deposition material; generating an arc at the working cathode surface to evaporate the first deposition material and the second deposition material; and depositing the evaporated first deposition material and second deposition material on the substrate. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] These and other features, aspects, and advantages of the present disclosure will be better understood when the following detailed description is read with reference to the accompanying drawings, in which like characters represent like parts throughout the drawings, wherein:

[0013] Figure 1 is a schematic diagram of an exemplary ion plasma deposition (IPD) apparatus;

[0014] Figure 2 is a perspective view of an exemplary cathode that can be used in the Figure 1 illustrated IPD apparatus;

[0015] Figure 3 is Figure 2 an exploded view of the illustrated cathode;

[0016] Figure 4 is Figure 2 and Figure 3 an exemplary top view of a first alternative embodiment of the cathode of

[0017] Figure 5 is Figure 2 and Figure 3 an exemplary top view of a second alternative embodiment of the cathode of

[0018] Figure 6 Is Figure 2 And Figure 3 An exemplary top view of a third alternative embodiment of the cathode of

[0019] Figure 7 Is Figure 2 And Figure 3 An exemplary top view of a fourth alternative embodiment of the cathode of

[0020] Figure 8 Is Figure 2 And Figure 3 An exemplary top view of a fifth alternative embodiment of the cathode of; and

[0021] Figure 9 Is a flow chart of an exemplary method of depositing a coating on a substrate.

[0022] Corresponding reference characters used in all the figures indicate corresponding parts. Unless otherwise indicated, the figures provided herein are intended to illustrate features of embodiments of the present disclosure. It is believed that these features are applicable to a wide variety of systems including one or more embodiments of the present disclosure. Accordingly, the figures are not intended to include all conventional features known to those of ordinary skill in the art that are required to practice the embodiments disclosed herein. Detailed Description

[0023] The exemplary embodiments described herein relate to systems and methods for depositing coatings on substrates using an ion plasma deposition (IPD) process, also known as cathodic arc deposition or vacuum arc deposition. The IPD process can be used to deposit metallic and / or non-metallic coatings. In some embodiments, the IPD process can be used to deposit coatings on components used in turbine engines, such as hot gas path components, like turbine blades or nozzle vanes. Turbine engine components can be designed for use in high temperature and highly oxidizing environments, and the components can be made of nickel, cobalt, and / or iron-based alloys or refractory metal-based alloys that are resistant to such environments. The IPD process can be used to deposit additional heat-resistant and / or wear-resistant coatings on turbine engine components to protect the underlying alloys from oxidation and thermally induced corrosion. Additionally or alternatively, the deposited coatings can also act as a bond coat for retaining corrosion-resistant coatings. Suitable deposited corrosion-resistant coatings for use in turbine engine applications can include, but are not limited to, only: nickel aluminide-based coatings, which can be modified by adding platinum to form platinum nickel aluminide-based coatings; and / or coatings of alloys containing chromium, aluminum, and at least one of iron, nickel, and cobalt. Compared to known physical vapor deposition techniques, such as electron beam physical vapor deposition (EBPVD) and / or chemical vapor deposition techniques, the IPD process can be a suitable alternative for depositing such corrosion-resistant coatings, both of which are limited in their ability to produce and maintain compositional control of the compositional complexity required for these corrosion-resistant coatings.

[0024] The IPD process is a physical vapor deposition process that isolates an arc (or cathodic arc) on the working surface of a cathode. The cathode is positioned in a vacuum chamber, which can act as the anode when a current is supplied to the cathode to generate an arc. When the arc traverses the working cathode surface, high-energy ions are ejected from the working surface and accelerated towards the substrate to be coated. Solids evaporated from the working cathode surface are converted into vapor and then re-condensed on the substrate to deposit as a coating. The cathode is fabricated (e.g., cast, forged, or powder pressed) from a deposition material (e.g., a metal or metal alloy) having a composition selected to achieve the desired composition of the deposited coating. However, significant technical challenges can arise related to the fabrication and / or use of the cathode. For example, depending on the composition of the coating, it may be difficult or impossible to fabricate the cathode from the deposition material required to produce the coating. The composition of the required deposition material can be such that the cathode made of the deposition material does not have sufficient strength and / or ductility to withstand the mechanical loads and stresses experienced during the fabrication and / or use of the cathode without prematurely cracking, which can result in unacceptable yield losses, poor coating quality, and / or no material transfer from the cathode during the IPD process.

[0025] The exemplary systems and methods described herein include using a "hybrid" cathode that includes a body made of a first deposition material and at least one insert made of a second deposition material coupled to the body, where the second deposition material is different from the first deposition material. The first deposition material and the second deposition material are each capable of being appropriately evaporated in response to an arc generated at the working surface of the cathode for depositing a coating on a substrate that includes the first deposition material and the second deposition material. The first deposition material and the second deposition material may be incompatible with each other such that a cathode made from a mixture of the first deposition material and the second deposition material (e.g., cast, forged, or powder pressed) may not have sufficient strength and / or ductility to withstand the mechanical loads and stresses experienced during the manufacture and / or use of the cathode without splitting prematurely. Coupling at least one insert made of the second deposition material to the body made of the first deposition material ensures that the incompatible deposition materials contained in the cathode remain separated until they are evaporated and deposited on the substrate. Thus, by enabling different, incompatible materials to be mechanically coupled to the body of the cathode, the exemplary hybrid cathode enables the "regulation" of the deposition material composition contained in the cathode for deposition on a substrate. In some embodiments, the body of the cathode may be machined (e.g., drilled) to form an opening or hole in the working cathode surface. An insert (e.g., a rod, post, or stud) made of a different material is inserted into and retained within the opening. The insert may be forced into the corresponding opening and retained therein via a friction fit. Additionally or alternatively, the insert may be retained in the corresponding opening using threads. Such inserts may also be easily removed from the body and replaced with other inserts made of other materials for deposition. Since the cathode can be used to quickly and accurately adjust the chemical composition without waiting to fabricate additional cathodes, such cathodes can be particularly useful for research and other applications where it may be advantageous to use a wide variety of materials in a single cathode. In some embodiments, the hybrid cathode may also be configured in a manner such that the cathode arc can be controlled as it circumscribes the working cathode surface. For example, the working cathode surface may be "concave" or "sunk" such that the cathode arc is driven towards the central region of the working cathode surface to ensure uniform erosion or evaporation, or otherwise prevent the cathode arc from accumulating in undesirable locations on the working cathode surface. Additionally or alternatively, the movement of the cathode arc may be controlled using insulating inserts coupled to the body and strategically positioned to control the arc movement. The insulating inserts may be made of an insulating material that the cathode arc will avoid and thus be deflected towards other regions on the working cathode surface. The insulating material may be alumina, boron nitride, or another suitable insulating material that will not support the cathode arc. In this manner, the hybrid cathode can be adjusted to "force" the cathode arc to uniformly and effectively evaporate the desired materials contained in both the body and the deposition material inserts.

[0026] Exemplary hybrid cathodes overcome at least some of the current limitations of the IPD process, including facilitating cost reduction and overcoming the problem of not being able to deposit coatings with complex compositions. Additionally, the exemplary hybrid cathodes enable additional deposition materials to be used in the coating process and enable the IPD process to be operated for longer periods of time without having to replace the cathode, and thus significantly affect the costs associated with the IPD process. Further, by configuring the cathode to control the movement of the cathode arc at the working surface, a more uniform and improved coating material can be deposited.

[0027] When introducing elements of the various embodiments disclosed herein, the articles "a", "an", "the", and "said" are intended to mean that there is one or more of the elements and include plural references, unless the context clearly dictates otherwise. "Optional" or "optionally" means that the subsequent described event or circumstance may or may not occur, and the description includes instances where the event occurs and instances where the event does not occur. Additionally, a reference to "one embodiment" is not intended to be construed as excluding the existence of additional embodiments that also incorporate the stated features. Further, unless there is a clear contrary indication, the terms "comprising", "including", and "having" are intended to be inclusive and mean that additional elements may exist in addition to the listed elements.

[0028] Unless otherwise indicated, approximate language, such as "substantially", "essentially", "about", and "approximately" as used herein, indicates that, as would be recognized by one of ordinary skill in the art, the so-modified term may apply only to an approximate degree and not an absolute or perfect degree. Thus, a value modified by one or more of the terms, such as "about", "approximately", and "substantially", is not limited to the specified exact value. In at least some instances, the approximate language may correspond to the precision of the instrument used to measure the value.

[0029] Unless otherwise indicated, the terms "first", "second", etc. are used herein only as labels and are not intended to impose an order, position, or grading requirement on the items to which these terms refer. Additionally, for example, a reference to a "second" item does not require or exclude the existence of, for example, a "first" or lower-numbered item or a "third" or higher-numbered item.

[0030] Referring now to the drawings, Figure 1 is a schematic diagram of an exemplary ion plasma deposition (IPD) device 100, which may include in addition to the reference Figure 1Additional components or other components beyond those shown and described so that the IPD device 100 can function as described herein. The IPD device 100 may also be referred to as a cathodic arc deposition device or a vacuum arc deposition device. In an exemplary embodiment, the IPD device 100 includes a vacuum chamber 102 that is in fluid communication with a vacuum system 104. The vacuum system 104 is operable to create a vacuum in the vacuum chamber 102, i.e., to create a partial pressure below atmospheric pressure in the vacuum chamber.

[0031] The IPD device 100 also includes a cathode 106 positioned within the vacuum chamber 102. The cathode 106 is made of any material (e.g., metal or metal alloy) suitable for deposition on a workpiece 108 (also referred to herein as a substrate 108) using the IPD device 100. The workpiece 108 is also positioned within the vacuum chamber 102 at a distance from the cathode 106. In an exemplary embodiment, the cathode 106 is located above the workpiece 108, but in other embodiments, the relative positioning between the cathode 106 and the workpiece 108 within the vacuum chamber 102 may vary. In addition to the cathode 106 and the workpiece 108, the vacuum chamber 102 may also contain an anode (not shown). The anode may be a conductive surface of the vacuum chamber 102 or may be a separate anode within the vacuum chamber. The anode is provided to absorb electrons from the cathode 106 to maintain the discharge generated at the cathode during the IPD process. In some embodiments, the workpiece 108 may be used as the anode within the vacuum chamber 102.

[0032] The workpiece 108 may be any article or component on which a coating (e.g., a metal or metal alloy coating) is deposited using the IPD device 100. The workpiece 108 may be suitably made of a metal or metal alloy material. The coating deposited on the workpiece 108 from the cathode 106 using the IPD device 100 may provide a protective layer or a layer for some other function on the surface of the workpiece. In some embodiments, the workpiece 108 is a component used in a high-temperature and / or oxidizing environment of a rotating machine, and the coating deposited from the cathode 106 provides a corrosion-resistant layer across the surface of the component. For example, the workpiece 108 may be a component used in a combustion chamber or a hot gas path of a turbine engine, such as a turbine blade, vane, nozzle, gasket, transition piece, etc. In such embodiments, the workpiece 108 may comprise at least one of a nickel alloy, an iron alloy, a cobalt alloy, and a nickel-iron alloy, including but not limited to only high-strength, high-temperature alloys also known in the art as "superalloys". Such superalloys may contain about 50% or more by weight of nickel, cobalt, iron, or nickel-iron, plus alloying elements added to improve the mechanical and physical properties of these alloys. For example, in some embodiments, the workpiece 108 may be made of a nickel-based superalloy, such as René N4 TM 、René N5 TM 、René 108 TM, and IN-738. René N4 TM , René N5 TM , René108 TM and / or and / or including γ'-strengthened nickel-based superalloys. In some embodiments, the workpiece 108 can be made of a cobalt-based superalloy such as FSX-414. In other embodiments, the workpiece 108 can comprise a refractory metal-based alloy, such as an alloy containing one or more of niobium, molybdenum, tantalum, tungsten, rhenium, titanium, vanadium, chromium, zirconium, hafnium, ruthenium, rhodium, osmium, and iridium. Although certain alloys have been described herein with respect to the workpiece 108, it should be understood that these alloys are merely exemplary and are not intended to be limiting. The materials used can vary depending on the intended application of the workpiece 108.

[0033] The IPD device 100 can be used in applications where a coating is deposited on a newly manufactured workpiece 108 and / or in applications where a coating is deposited on a workpiece that has previously been used in operation. For example, the IPD device 100 is suitable for the repair process of workpieces 108 that have previously been installed and used in high-temperature and / or oxidizing environments, such as turbine components previously used in the hot gas path or combustion chamber of a turbine engine. Thus, in certain embodiments, the workpiece 108 may already include at least one coating before being positioned in the vacuum chamber 102. Depending on the composition and condition of the existing coating on the workpiece 108, the existing coating can be removed before performing the IPD process using the device 100, or the IPD process can be performed on the workpiece without removing the existing coating.

[0034] The exemplary cathode used as the cathode 106 will be described in more detail below (with reference to Figures 2 to 8 ). Generally, in the exemplary embodiment, the cathode 106 includes a material suitable for depositing a coating on the workpiece 108, and the coating has a composition that enables the coating to function as desired. The material contained in the cathode 106 can be referred to herein as the cathode material or deposition material. The specific composition of the cathode 106 can depend on several factors, including but not limited to only the type of the workpiece 108 and the type of environmental exposure that the workpiece 108 is expected to endure during use. In various examples, the cathode 106 can contain, but is not limited to, one or more elements selected from nickel, aluminum, cobalt, chromium, molybdenum, tungsten, rhenium, ruthenium, zirconium, hafnium, tantalum, silicon, yttrium, titanium, lanthanum, cerium, niobium, vanadium, platinum, iridium, osmium, palladium, rhodium, and / or combinations thereof. The cathode 106 can contain additional and / or alternative elements, such as carbon and boron, depending on the desired application of the coating.

[0035] The cathode 106 can be formed into any shape suitable for use in the IPD device 100, such as but not limited to a cylinder. The cathode 106 is formed to have an end face 118 from which the material of the cathode is eroded or evaporated for depositing a coating on the workpiece 108. The end face 118 can also be referred to as the working surface 118 of the cathode 106. Metallurgical and manufacturing processes, such as for example casting and powder metallurgy processing, are suitable for manufacturing the body (e.g., the main cylindrical portion) of the cathode 106 from a mixture of cathode materials for deposition. However, such techniques are typically limited because the materials incorporated into the cathode 106 from the mixture must be compatible with each other. If the materials are incompatible, the cathode 106 may not have sufficient strength and / or ductility and may split prematurely (i.e., fail) during or prior to the IPD process.

[0036] Thus, as described in further detail below, the exemplary cathode 106 used in the exemplary IPD device 100 includes one or more inserts (e.g., the insert 218 most visibly shown in Figure 3 made of an additional deposition material that is incompatible with the deposition material contained in the body of the cathode 106. Such an insert 218 is coupled to the body of the cathode 106 such that the incompatible deposition materials contained in the insert 218 and the body of the cathode 106 can be simultaneously deposited in the coating without causing the cathode 106 to split prematurely (i.e., fail). Thus, the exemplary cathode 106 described herein facilitates the deposition of a wide variety of coating compositions and increases the degree of flexibility of the IPD process. Additionally, the insert 218 can be selectively installed in and removed from the body of the cathode 106 such that this portion of the cathode 106 can be recovered and reused together with inserts made of other deposition materials. Thus, the exemplary cathode 106 facilitates reducing costs and overcoming the limitations of known IPD devices, as well as facilitating the controllable incorporation of incompatible materials into a single cathode having the strength and / or ductility suitable for manufacturing and use in the IPD process.

[0037] In an exemplary embodiment, the cathode 106 can be supported in the vacuum chamber 102 by an evaporator plate 110. The evaporator plate 110 can be cooled via a cooling fluid supplier 112 that delivers cooling fluid to / from the evaporator plate 110. The cooling fluid supplied to the evaporator plate 110 can be circulated through internal channels (not shown) formed in the evaporator plate 110 to facilitate cooling during the operation of the IPD device 100.

[0038] The IPD device 100 also includes one or more power supplies 114, 116 (or current sources) that operate to generate a cathode arc (or arc) at the working cathode surface 118. The power supplies 114, 116 can be any source suitable for generating a cathode arc at the working cathode surface 118, such as a direct current (DC) power supply (e.g., an arc welder). In an exemplary embodiment, the cathode 106 containing the material to be deposited on the workpiece 108 is coupled to the first DC power supply 114. The amount of current supplied to the cathode 106 using the DC power supply 114 can be determined at least in part by the cathode material and the desired rate of erosion or evaporation of the coating material from the working cathode surface 118. The melting point of the cathode material can be a factor in determining the current suitable to supply to the cathode 106. A greater or lesser current can be supplied to the cathode 106 to selectively increase or decrease the erosion or evaporation rate.

[0039] A second DC power supply 116 coupled to the workpiece can be used to induce a negative voltage bias on the workpiece 108. In other embodiments, the second DC power supply 116 can be coupled to an anode (not shown) contained within the vacuum chamber 102, or can be omitted from the IPD device 100. In some embodiments, the cathode 106 and the workpiece 108 (or other anode) can be coupled to opposite terminals of a single power supply such as the DC power supply 114 or 116. A negative voltage bias can be applied to the workpiece 108 to affect material deposition by increasing the attraction of ions and charged particles from the working cathode surface 118 to the workpiece 108. Applying a negative voltage bias can additionally or alternatively heat the workpiece 108 and can cause the temperature of the workpiece 108 to increase during the IPD process. This heating of the workpiece 108 can cause interdiffusion and reaction between the elements of the deposited material and the elements of the material of the workpiece to form a coating composition in situ on the workpiece. The specific value selected for the voltage bias can depend on various factors, including for example the amount and type of interaction desired to occur between the deposited material and the material of the workpiece 108.

[0040] In the operation of the IPD device 100, the cathode 106 and the workpiece 108 are positioned within the vacuum chamber 102, as Figure 1As shown. The vacuum system 104 operates to create a vacuum within the vacuum chamber 102. Current is supplied from a first DC power source 114 to the cathode 106, for example, to create a sufficient potential between the cathode 106 and the workpiece 108 (and / or an anode positioned within the vacuum chamber 102). A negative voltage bias may also be supplied to the workpiece using, for example, a second DC power source 116. An arc (or cathode arc) is generated at the working cathode surface 118, causing erosion or evaporation of the cathode material from the working cathode surface. The cathode current converges at tiny, extremely high-energy cathode arc spots, and highly ionized metal plasma is generated due to the erosion or evaporation of the cathode material at the working cathode surface 118. After the cathode arc forms, it persists for a short period of time and then extinguishes, quickly reforming again, thus giving the illusion of the arc continuously moving over the working cathode surface 118. The erosion or evaporation of the cathode material at the working surface 118 forms a cloud of droplets and ions of the coating material within the vacuum chamber 102 (indicated by the arrow 120 in Figure 1 ). The cloud 120 of the coating material contains ions, charged particles, vapor, and neutral droplets in the vacuum environment. The coating material 120 is deposited on the surface of the workpiece 108 from the cloud via condensation and / or electrostatic attraction. The electrostatic attraction can be controlled (e.g., increased) using the negative voltage bias applied to the workpiece 108 to facilitate the attraction of charged particles within the cloud 120 of the coating material to the surface of the workpiece. Thus, a coating is deposited on the workpiece 108, and its desired thickness can be determined by factors such as, for example, the intended application of the coated workpiece 108. The thickness of the coating deposited on the workpiece 108 can be controlled based on various IPD process parameters, such as the duration of the IPD process, the pressure within the vacuum chamber, the current supplied to the cathode 106, the material contained within the cathode, the ground potential or negative voltage bias applied to the workpiece 108, and / or other process parameters. The cathode 106 and / or the workpiece 108 can be rotated on a planetary gear (not shown) to provide a uniform coating on the workpiece.

[0041] Figure 2 and Figure 3 illustrates an exemplary cathode 200 that can be used as the cathode 106 in the IPD device 100 ([[]]shown in Figure 1 ). Figure 2 is a perspective view of the exemplary cathode 200, and Figure 3It is an exploded view of the cathode 200. In an exemplary embodiment, the exemplary cathode 200 includes a body 202 that is cylindrical in shape and defines two end surfaces 204 and 206 and a circumferential edge 208 extending between the end surfaces 204, 206. In other examples, the body 202 of the cathode 200 can have any other suitable shape that enables the cathode to function as described herein. For example, the body 202 of the cathode 200 can be another prismatic shape having any suitable cross-sectional shape (e.g., oval, square, rectangular, or another polygonal shape) and includes a pair of end surfaces 204, 206 and side edges 208 extending therebetween. The cathode 106 can be appropriately sized depending on, for example, the desired thickness of the deposited coating.

[0042] The first end surface 204 defines the working cathode surface of the cathode 200 and serves as the working cathode surface 118 when the cathode 200 is used in the ( Figure 1 shown) IPD device 100. Thus, during the IPD process using the cathode 200, a cathode arc is generated at the working cathode surface 204 as described above, and the material at the working cathode surface 204 is eroded or evaporated for deposition on the workpiece 108. The second end surface 206 can be coupled to a component of the IPD device 100 (e.g., the evaporator plate 110) for positioning the cathode 200 in the vacuum chamber 102. The second end surface 206 can be substantially flat or can have features (e.g., contours, slots, etc.) that enable the cathode 200 to be coupled to the IPD device 100 within the vacuum chamber 102.

[0043] As Figure 2 shown, the working cathode surface 204 can be "concave" or "sunken". Specifically, the working cathode surface 204 of the exemplary cathode 200 includes a peripheral edge 210 adjacent to the circumferential edge 208 of the body 202 and a recessed surface 212 that is lowered relative to the peripheral edge 210. A downwardly extending surface 214 can extend between the recessed surface 212 and the peripheral edge 210. Any suitable machining technique can be used to form the recessed surface 212 and the downwardly extending surface 214 located between the circumferential edge 208 and the recessed surface 212. Suitable machining techniques include, but are not limited to, hand grinding, milling, electrical discharge machining, etc. The recessed surface 212 can form the main area of the working cathode surface 204, and this main area extends greater than about 50% of the radial distance (or diameter) of the working cathode surface. In other words, the distance spanned by the downwardly extending surface 214 and the peripheral edge 210 between the recessed surface 212 and the circumferential edge 208 can be less than about 50% of the radial distance (or diameter) of the working cathode surface 204.

[0044] The surface 214 can be an inclined surface between the peripheral edge 210 and the recessed surface 212, and can be referred to as the inclined surface 214. The angle of the inclined surface 214 can vary and can be selected according to the desired "sinking" of the recessed surface 212 from the peripheral edge 210. In various examples, the inclined surface 214 can extend at an angle within a range of about 10° to about 80°. A relatively steeper angle of the inclined surface 214 provides a greater sinking of the recessed surface 212, and a relatively shallower angle of the inclined surface provides a smaller sinking of the recessed surface.

[0045] The recessed surface 212 can be substantially flat within the range between the downwardly extending surfaces 214, except for the holes or openings 216 ( Figure 3 as shown) formed in the recessed surface 212, which receive corresponding inserts 218 made of additional cathode or deposition material, as will be described in further detail below. The peripheral edge 210 can be substantially flat within the range between the circumferential edge 208 and the downwardly extending surfaces 214. In some embodiments, the downwardly extending edge 214 can be omitted, and the working cathode surface 204 can be integrally concave to form a mid-recessed or sunken shape. In other embodiments, the working cathode surface 204 can be substantially flat within the range between the circumferential edges 208 of the body 202, except for the openings 216 formed in the working cathode surface for receiving the corresponding inserts 218. The desired shape of the working cathode surface 204 can be provided by any suitable machining technique such as, for example, hand grinding, milling, electrical discharge machining, etc. Such machining techniques can also be used to form the openings 216.

[0046] Suitably, a mid-recessed or sunken shape of the working cathode surface 204 is provided to facilitate control of the movement of the cathode arc during the IPD process. Specifically, the shape of the working cathode surface 204 can drive the cathode arc towards the central region (e.g., the recessed surface 212) of the working cathode surface to facilitate control of the erosion or evaporation of the working cathode surface and / or to prevent the cathode arc from accumulating at spots along the periphery of the working cathode surface and near the circumferential edge 208 of the body 202. This can be beneficial for increasing the life of the cathode 200 and / or improving the material transfer from the cathode during the IPD process.

[0047] The body 202 of the cathode 200 can be manufactured using suitable techniques, including but not limited to those involving only metallurgical and manufacturing processes such as casting and powder metallurgy processing. Suitable machining techniques such as hand grinding, milling, electrical discharge machining, etc. can also be used to machine the body 202 into the desired shape and size, and / or to machine the surfaces (e.g., the first end surface 204, the second end surface 206, and the circumferential edge 208) of the body 202 into the desired shape and / or final finish.

[0048] The body 202 of the cathode 200 is made of a first deposition material that is capable of evaporating in response to an arc generated at the working cathode surface 204 and is suitable for deposition on a substrate using an IPD process. The first deposition material may include, but is not limited to, only one or more elements selected from nickel, aluminum, cobalt, chromium, molybdenum, tungsten, rhenium, ruthenium, zirconium, hafnium, tantalum, silicon, yttrium, titanium, lanthanum, cerium, niobium, vanadium, platinum, iridium, osmium, palladium, rhodium, carbon, boron, and / or combinations thereof. In an example where the first deposition material includes a combination of elements (e.g., an alloy), these elements are suitably compatible with each other in their respective amounts. As used herein, the term "compatible" refers to elements and / or alloys that can be mixed in their respective amounts and used to fabricate (e.g., by casting, forging, or powder pressing) a solid structure (e.g., the body 202 or insert 218 of the cathode 200) of the cathode 200 that has sufficient strength and / or ductility to withstand the mechanical loads experienced during the manufacture and / or use of the cathode without prematurely splitting (i.e., failing). As used herein, "incompatible" elements and alloys cannot actually be mixed in their respective amounts and used to fabricate (e.g., by casting, forging, or powder pressing) a solid structure (e.g., the body 202 or insert 218 of the cathode 200) of the cathode 200 that has sufficient strength and / or ductility to withstand the mechanical loads experienced during the manufacture and / or use of the cathode without prematurely splitting (i.e., failing). Thus, when the body 202 is made of a first deposition material that includes a mixture of compatible elements, the body 202 has sufficient strength and / or ductility to prevent the body 202 from failing, while when the body 202 is made of a first deposition material that includes a mixture of incompatible elements, the body 202 has a greater tendency to fail.

[0049] In an exemplary embodiment, the cathode 200 further includes one or more inserts 218 coupled to the body 202. The inserts 218 may also be referred to herein as deposition inserts. Each insert 218 is made of a deposition material that, similar to the first deposition material, is capable of evaporating in response to an arc generated at the working cathode surface 204 and is suitable for deposition on a substrate using an IPD process. Suitably, the deposition material used to fabricate each insert 218 is different from the first deposition material (e.g., is a different element or alloy). The deposition material used to fabricate each insert may include, but is not limited to, only one or more elements selected from nickel, aluminum, cobalt, chromium, molybdenum, tungsten, rhenium, ruthenium, zirconium, hafnium, tantalum, silicon, yttrium, titanium, lanthanum, cerium, niobium, vanadium, platinum, iridium, osmium, palladium, rhodium, carbon, boron, and / or combinations thereof. In an example where the deposition material used to fabricate one or more of the inserts 218 includes a combination of elements (e.g., an alloy), these elements are suitably compatible with each other.

[0050] In an exemplary embodiment, the deposition material used to fabricate one or more of the inserts 218 may be incompatible with the first deposition material contained in the body 202 of the cathode 200. For example, the deposition material used to fabricate each insert 218 may be an element or alloy that provides sufficient strength and / or ductility to prevent the insert 218 from failing, but when the element or alloy is mixed with the first deposition material and the mixture is used to fabricate (e.g., by casting, forging, or powder pressing) the body 202, the body 202 has a greater tendency to fail. The deposition material used to fabricate the inserts 218 that are mechanically coupled to the body 202 of the cathode 200 remains separate (or unmixed) from the first deposition material of the body 202 until they evaporate and deposit during the IPD process. Thereby, the inserts 218 enable incompatible deposition materials (e.g., incompatible elements and / or incompatible alloys) to be deposited simultaneously with the first deposition material using the cathode 200 via the IPD process. Thus, providing the inserts 218 that are mechanically coupled to the body 202 enables a wide variety of deposition coating compositions and increases the degree of flexibility of the IPD process.

[0051] Each of the inserts 218 may include the same deposition material, or the inserts 218 may include different deposition materials. In some embodiments, one or some of the inserts 218 may be made of a deposition material that is incompatible with the deposition material of another insert 218. The inserts 218 may be fabricated and machined into a desired size and shape using techniques similar to those described above for the body 202. For example, the inserts 218 may be fabricated from a desired deposition material using casting or powder metallurgy processes and then machined into a desired size and shape using hand grinding, milling, electrical discharge machining, etc. Additionally or alternatively, the inserts 218 may be obtained as solid stock of the deposition material from a commercial supplier and optionally further machined into a desired size and shape.

[0052] In Figure 2 and Figure 3 the illustrated example, the cathode 200 includes three inserts 218. In other embodiments, such as those described below with reference to Figures 4 to 8In the embodiments described, the number of inserts 218 may vary. Any suitable number of inserts 218 may be included in the cathode 200, and the number of inserts 218 may vary depending on the deposition material contained in the cathode 200, the desired composition of the coating deposited using the IPD process, and the size of the inserts 218. In various examples, the number of inserts 218 included in the cathode 200 may be one or more than one (such as two, three, four, five, six, seven, eight, nine, ten, or more than ten) inserts 218. In cases where relatively small inserts 218 are used, a relatively large number of inserts 218 may be included (e.g., more than ten, more than twenty, or more than fifty).

[0053] In an exemplary embodiment, each insert 218 is coupled to the body 202 of the cathode 200 by positioning the insert 218 in a corresponding opening 216 formed in the working cathode surface 204. The opening 216 may also be referred to as a hole 216. The insert 218 is inserted into the corresponding hole or opening 216 and retained therein to couple the insert to the body 202. The insert 218 may be forced (or pressed) into the corresponding opening 216 and retained therein via a friction fit (or press fit). In these examples, each insert 218 and the corresponding opening 216 are sized appropriately such that the insert is retained within the corresponding opening and does not prematurely disengage from the body 202. Additionally and / or alternatively, the insert 218 may be retained in the corresponding opening 216 using threads (i.e., via a threaded engagement between the insert and the threads within the corresponding opening). In these examples, each insert 218 and the corresponding opening 216 are sized appropriately and have corresponding threads such that the insert is threadedly retained within the corresponding opening and does not prematurely disengage from the body 202. Any suitable attachment means may be used to couple the insert 218 to the body 202. In some examples, the insert 218 is suitably coupled to the body 202 without the use of additional mechanical elements, adhesives, etc. This may be beneficial in reducing the tendency of any external elements used to couple the insert 218 to the body 202 to interfere with the cathode arc during the IPD process.

[0054] As Figure 3 shown, each insert 218 may be in the shape of a cylindrical rod and have opposite end surfaces 220, 222. The length of each insert 218 (measured between the opposite end surfaces 220, 222) may be substantially equal to or less than the length of the body 202 of the cathode 200. The size and shape of the insert 218 may vary (see, for example Figure 6) For example, the insert 218 may have a varying cross-sectional shape, diameter, and / or length. The size and shape of each insert 218 may be determined based on the desired amount of deposition material of the corresponding insert to be included in the deposited coating. In other words, the size of the insert 218 containing deposition material intended to be included in a larger amount in the deposited coating may be larger than the insert containing deposition material intended to be included in a smaller amount. The size and shape of the corresponding opening 216 may also vary according to the size and shape of the corresponding insert 218 such that the insert can be coupled to the body 202 as described herein.

[0055] When each insert 218 is coupled to the body 202 of the cathode 200, the first end surface 220 of the insert 218 is exposed at the working cathode surface 204. The first end surface 220 of the insert 218 may also be referred to as the exposed surface 220 or the exposed portion 220 of the insert 218. Each exposed surface 220 is eroded or evaporated by a cathodic arc generated at the working cathode surface 204 during the IPD process. The opposite second end surface 222 of each insert 218 may extend to the second end surface 206 of the body 202 of the cathode 200 or, in the case where the length of the insert is shorter than the body, may terminate before the second end surface of the body.

[0056] Each insert 218 may be machined (e.g., by hand grinding, milling, electrical discharge machining, etc.) such that the exposed surface 220 matches the profile of the working cathode surface 204. In an exemplary embodiment, as Figure 2As shown, each exposed surface 220 of the insert 218 is located at the recessed surface 212 and can be machined to be substantially flat and flush with the recessed surface. Appropriately, in an embodiment where the working cathode surface 204 is concave or sunken, the exposed surface 220 of the insert 218 is located radially inward of the downwardly extending surface 214 such that the exposed portion is in the path of the cathode arc controlled by the concave or sunken shape of the working cathode surface. In other embodiments where the working cathode surface 204 is concave or sunken, the exposed surface 220 of the insert 218 can be at least partially located at the downwardly extending surface 214 and / or the peripheral edge 210. In these embodiments, the surface 220 can be machined to match the profile (e.g., bevel) of the radially outer portion of the working cathode surface 204. In other embodiments, the working cathode surface 204 can be integrally concave to form a concave or sunken shape, and the exposed surface 220 of the insert 218 can be machined to match the concave shape of the working cathode surface. In other embodiments, the working cathode surface 204 can be substantially flat within the range between the circumferential edges 208 of the body 202, and the exposed surface 220 of the insert 218 can be machined to match the substantially flat shape of the working cathode surface. In embodiments where the working cathode surface 204 is integrally concave or substantially flat, one or some of the inserts 218 can be located at the radially outer portion of the working cathode surface near the circumferential edge 208 of the body 202.

[0057] Now referring Figures 4 to 8 , various exemplary alternative embodiments of the cathode 200 shown in Figure 2 and Figure 3 will now be described, which have different exemplary configurations of the insert 218. Figures 4 to 8 Each figure in Figure 3 shows a top view of an embodiment of the cathode 200, which shows the working cathode surface 204 of the body 202 and the exposed surface 220 of the insert 218 at the working cathode surface. The insert 218 is coupled to the body 202 as described above. In an exemplary embodiment, the insert 218 is received within a corresponding opening 216 formed in the working cathode surface 204 (shown in Figures 2 to 8 ) and is retained therein via a friction fit (or press fit) or using threads. It should be understood that the exemplary embodiments of the cathode 200 in

[0058] In each alternative embodiment, the working cathode surface 204 may include the concave or recessed shape described above, examples of which are shown in Figure 2 . In these embodiments, the exposed surface 220 of the insert 218 may be located at and substantially flush with the recessed surface 212 and radially inward of the downwardly extending surface 214. Additionally or alternatively, the exposed surface 220 of the insert 218 may be at least partially located at the downwardly extending surface 214 and / or the peripheral edge 210. In other embodiments, the working cathode surface 204 may be substantially flat or overall concave. The exposed surface 220 of the insert 218 may be machined as described above to match the profile (e.g., flat, beveled, concave) of the location where the exposed surface of the working cathode surface 204 is located.

[0059] Figure 4 is a first exemplary alternative embodiment of the cathode 200, generally designated 200a. In this embodiment, the cathode 200a includes four inserts 218 coupled to the body 202. More or fewer inserts 218 may be included in the cathode 200a. The body 202 and the four inserts 218 each contain the deposition material described above. The deposition material of each of the four inserts 218 may be the same as or different from the deposition material of the other inserts 218. In some embodiments, at least one of the four inserts 218 contains a deposition material that is incompatible with the deposition material contained in the body 202 and / or the deposition material contained in one or more of the other inserts 218. In Figure 4 the illustrated embodiment, the four inserts 218 are coupled to the body 202 such that the exposed surfaces 220 are circumferentially arranged or spaced apart at the working cathode surface 204. The circumferential arrangement of the exposed surfaces 220 of the inserts 218 may follow the path that the cathode arc travels at the working cathode surface 204 during the IPD process, which may be at least partially guided by the sinking or concave shape of the working cathode surface. In other embodiments, the inserts 218 may be arranged in any pattern suitable for the cathode 200a to function as described herein.

[0060] Figure 5 is a second exemplary alternative embodiment of the cathode 200, generally designated 200b. In this embodiment, the cathode 200b includes four inserts 218 that are coupled to the body 202 and have exposed surfaces 220 that are circumferentially arranged or spaced apart at the working cathode surface 204, as described above for Figure 4as described for the cathode 200a. The body 202 and the four inserts 218 each contain the deposition material as described above, and at least one of the inserts 218 may contain a deposition material that is incompatible with the deposition material contained in the body 202 and / or the deposition material contained in another one or more of the inserts 218. Additionally, the cathode 200b of this embodiment includes an additional insert indicated at 224, which is made of an electrically insulating material that does not support cathodic arcs. In some examples, the additional insert 224 is made of alumina or boron nitride. The additional insert 224 may also be referred to as an electrically insulating insert or an insulating insert. The insulating insert 224 includes an exposed surface 226 at the working cathode surface 204. The insulating insert 224 may be configured similarly to the other inserts 218, for example, may be similar in shape (e.g., cylindrical rod) to the insert 218. The insulating insert 224 is coupled to the body 202 of the cathode 200b as described above for the insert 218. For example, the insulating insert 224 may be received in a corresponding opening 216 (shown in Figure 3 as shown) in the working cathode surface 204 and held therein by a friction fit (or press fit).

[0061] Suitably, the insulating insert 224 is provided to facilitate control of the movement of cathodic arcs at the working cathode surface 204 during the IPD process. As a complement or alternative to the concave or recessed shape of the working cathode surface 204, the insulating insert 224 may be included. The electrically insulating material (e.g., alumina or boron nitride) of the insulating insert 224 repels the cathodic arcs at the working surface 204 and drives the cathodic arcs away from the insulating insert and towards other regions of the working cathode surface 204. In this way, providing the insulating insert 224 facilitates control of the movement of cathodic arcs at the working cathode surface, for example, to achieve more uniform erosion or evaporation of the working cathode surface, and helps prevent the cathodic arcs from aggregating at undesired locations along the working cathode surface. This can help increase the lifespan of the cathode 200b and improve the material transfer from the cathode during the IPD process.

[0062] In the illustrated cathode 200b, a single insulating insert 224 is included, and the single insulating insert is coupled to the body 202 such that the exposed surface 226 of the insulating insert is positioned in the central region of the working cathode surface 204. The exposed surface 220 of the insert 218 and the deposition material of the body 202 are located radially outside of the insulating insert 224. In this manner, during the IPD process, the cathode arc generated at the working cathode surface 204 avoids the insulating material (e.g., alumina or boron nitride) of the insulating insert 224 and encircles the central region of the working cathode surface to erode or evaporate the body and the deposition material contained in the insert around the exposed surface 226 of the insulating insert. The circumferential movement of the cathode arc around the insulating insert 224 can be further controlled by the concave or sunken shape of the working cathode surface 204. That is, while the insulating insert 224 operates to control the outward radial movement of the cathode arc from the insulating insert, the concave or sunken shape of the working cathode surface 204 drives the cathode arc radially inward. In this manner, the insulating insert 224 and the concave or sunken shape of the working cathode surface 204 cooperate to control the movement of the cathode arc such that the cathode arc converges along a circumferential path (indicated by the arrow 228 in Figure 5 ), which circumferential path is located, for example, between the insulating insert and the downwardly extending surface 214. Suitably, the exposed surface 220 of the insert 218 is located at the region of the working cathode surface 204 where the convergence of the cathode arc is controlled.

[0063] As Figure 5 shown, the movement controlled by the cathode arc using the insulating insert 224 and the working cathode surface 204 is provided by way of example only. More insulating inserts 224 may be included, or one or more of the insulating inserts 224 may have an exposed surface 226 at other locations at the working cathode surface 204 to control the desired movement of the cathode arc. The size and / or shape of the insulating insert 224 may also be adjusted (e.g., by changing the diameter of the exposed surface 226 at the working cathode surface 204) to control the movement of the cathode arc, as described herein. In addition, the insulating insert 224 may be sized appropriately to optimize the operable surface area of the working cathode surface 204 that contains the evaporable deposition material, while also enabling the insulating insert to function as described herein. As a complement or alternative to adjusting the shape of the working cathode surface 204, the configuration of the insulating insert 224 may be adjusted. In some embodiments, one or more insulating inserts 224 may be included and the working cathode surface 204 may be substantially flat. In these examples, a plurality of insulating inserts 224 may be provided, which are annular in shape and facilitate converging the cathode arc at an annular region located between the radially adjacent insulating inserts 224 (see Figure 8)。In this way, the insulating insert 224 and / or the shape of the working cathode surface can be used to finely adjust and control the movement of the cathode arc at the working cathode surface 204.

[0064] Figure 6 is a third exemplary alternative embodiment of the cathode 200, generally designated 200c. The cathode 200c is similar to the cathode 200a ( Figure 4 shown) and includes four inserts 218 that are coupled to the body 202 and have exposed surfaces 220 that are circumferentially arranged or spaced apart at the working cathode surface 204. As described above, the body 202 and the four inserts 218 each contain a deposition material, and at least one of the inserts 218 may contain a deposition material that is incompatible with the deposition material contained in the body 202 and / or the deposition material contained in another one or more of the inserts 218. The cathode 200c is illustrated as not having an insulating insert 224 ( Figure 5 shown), but may include an insulating insert in other examples. In this example, the inserts 218 have different cross-sectional shapes, as Figure 6 shown. The cross-sectional shapes are provided by way of example only, and the inserts 218 may have any suitable cross-sectional shape (e.g., circular, oval, triangular, square, rectangular, or another polygonal shape). The size and shape of the inserts 218 may vary depending on the deposition material contained in the insert and the desired amount of that deposition material in the deposited coating.

[0065] Figure 7 is a fourth exemplary alternative embodiment of the cathode 200, generally designated 200d. In this embodiment, the cathode 200d includes eight inserts 218, each insert including an exposed surface 220 that is radially outside of the insulating insert 224. The insulating insert 224 is positioned in the central region of the working cathode surface 204 as described above, and the inserts 218 are arranged such that the exposed surfaces 220 are circumferentially arranged around the insulating insert. In this example, the body 202 is made of a first deposition material, and the inserts 218 include a first insert 218a made of a second deposition material, a second insert 218b made of a third deposition material, and a third insert 218c made of a fourth deposition material. The inserts 218a - 218c are arranged in an alternating manner in the circumferential arrangement, as Figure 7as shown, but any arrangement of inserts 218a - 218c may be used. For example, the first insert 218a, the second insert 218b, and / or the third insert 218c may be grouped by similar materials (i.e., located near inserts 218a - 218c having similar deposited materials). In the illustrated cathode 200d, the inserts 218 are similarly sized and shaped, and inserts 218a and 218b included are more numerous than insert 218c. Thus, the second and third deposited materials included in the deposited coating are more than the fourth deposited material. The number of each type of insert 218a - 218c and their relative sizes may vary according to the desired amount of the corresponding deposited material included in the deposited coating. The second, third, and / or fourth deposited materials may be incompatible with the first deposited material of the body 202. Additionally and / or alternatively, the second deposited material may be incompatible with the third and / or fourth deposited materials, and / or the third and fourth deposited materials may be incompatible.

[0066] Figure 8 is a fifth exemplary alternative embodiment of cathode 200, indicated generally at 200e. In this embodiment, cathode 200e includes a body 202 made of a first deposited material, two insulating inserts 224 (labeled 224a and 224b), and an insert 218 made of a second deposited material. As described above, the first and second deposited materials may be incompatible with each other. Each of the insulating inserts 224a and 224b is made of an electrically insulating material that does not support a cathodic arc, such as alumina or boron nitride, for example. The insulating inserts 224a and 224b control the movement of the cathodic arc at the working cathode surface 204. The first insulating insert 224a is cylindrical in shape and is positioned in the central region of the working cathode surface 204. The second insulating insert 224b is annular and is positioned between the peripheral edge 210 of the body 202 and the remainder of the working cathode surface 204 that is radially between the insulating inserts 224a and 224b. In some embodiments, the annular insulating insert 224b may surround the body 202 of the cathode 200e, including the circumferential edge 208 ( Figure 2 and Figure 3 as shown). The region of the working cathode surface 204 between the insulating inserts 224a and 224b may be substantially flat. The insulating inserts 224a and 224b may cooperate to control the movement of the cathodic arc such that the cathodic arc follows a circumferential path (by Figure 8The arrow 228 in (indicates) the aggregation, and this circumferential path is located radially between the insulating inserts. Appropriately, the insert 218 made of the second deposition material is positioned between the insulating inserts 224a and 224b and along the region of the working cathode surface 204 where the aggregation of the cathode arc is controlled. In the exemplary cathode 200e, the insert 218 is annular. In other embodiments, more or fewer inserts 218 may be included. For example, a plurality of annular inserts 218 may be included, and these annular inserts may include the same or different deposition materials. Additionally and / or alternatively, the insert 218 of the cathode 200e may have any suitable size and / or shape. For example, the insert 218 may be shaped as shown in any of the figures in Figures 2 to 7 and as described above. The number, size, and / or shape of the insert 218 vary as described above according to the desired composition of the deposited coating.

[0067] Figure 9 Illustrates an exemplary method 300 of depositing a coating material on a substrate (such as the workpiece 108 described above with reference to Figure 1 ). The method 300 can be performed using the IPD device 100 (shown in Figure 1 ). The method includes: providing 302 a cathode (e.g., cathode 200), the cathode including a body (e.g., body 202) that defines a working cathode surface (e.g., working cathode surface 204). The body contains a first deposition material that can be evaporated in response to a cathode arc (or arc) generated at the working cathode surface. The method 300 further includes: coupling 304 at least one insert (e.g., at least one insert 218) to the body. The at least one insert can be coupled 304 to the body by forming a corresponding opening (e.g., opening 216) in the working cathode surface for each insert and positioning each insert in the corresponding opening. Each insert can be held in the corresponding opening by a friction fit (or press fit). The at least one insert contains a second deposition material that can be evaporated in response to a cathode arc (or arc) generated at the working cathode surface. The second deposition material is different from the first deposition material and may be incompatible with the first deposition material. When the at least one insert is coupled 304 to the body, the at least one insert is at least partially exposed at the working cathode surface (e.g., having an exposed surface 220).

[0068] Method 300 further includes: generating 306 an arc (or cathode arc) at the surface of the working cathode to evaporate the first deposition material and the second deposition material. To generate 306 the cathode arc, the cathode and the substrate can be positioned in a vacuum environment (e.g., within vacuum chamber 102) and a current can be supplied to the cathode (e.g., via DC power supply 114) to create a sufficient electrical potential between the cathode and the substrate. A ground electrical potential or a negative voltage bias can also be provided to the substrate, as described above. The cathode arc generated 306 at the surface of the working cathode erodes or evaporates the first deposition material of the body and the second deposition material of at least one insert. The erosion or evaporation of the first deposition material and the second deposition material forms a cloud of droplets and ions of the coating material, and the cloud of droplets and ions of the coating material is deposited 308 on the surface of the substrate by condensation and / or electrostatic attraction. The deposited coating contains the first deposition material and the second deposition material, and the first deposition material and the second deposition material can be incompatible and thus remain separated until the materials are evaporated, to facilitate reducing or preventing the cathode from prematurely splitting before or during the deposition process. In some embodiments, method 300 can include: controlling the movement of the cathode arc generated 306 at the surface of the working cathode. For example, method 300 can include: coupling an insulating insert (e.g., insulating insert 224) to the body such that the insulating insert is at least partially exposed at the surface of the working cathode (e.g., has an exposed surface 226), and using the insulating insert to control the movement of the arc at the surface of the working cathode. Additionally and / or alternatively, method 300 can include: forming a concave or sinking shape of the surface of the working cathode, and using the shape of the surface of the working cathode to control the movement of the arc at the surface of the working cathode.

[0069] The above-described systems and methods facilitate overcoming at least some of the limitations and costs associated with current IPD processes by using a “hybrid” cathode that includes a body made of a first deposition material and at least one insert made of a second different deposition material coupled to the body. The hybrid cathode enables the first deposition material and the second deposition material to be deposited on the substrate. Specifically, the exemplary hybrid cathode enables incompatible materials to be deposited on the substrate simultaneously from a single cathode, while facilitating reducing or eliminating the tendency of the cathode to prematurely split or fail before or during deposition. The second deposition material can be incompatible with the first deposition material because the incompatible deposition materials remain separated until they are evaporated and deposited on the substrate.

[0070] The insert coupled to the body can also be easily removed from the body and selectively replaced with an insert made of other materials for deposition, which can be beneficial to enable the use of a wide variety of materials in a single cathode. The exemplary hybrid cathode can also be configured in a manner such that the cathode arc can be controlled as it wraps around the working cathode surface (e.g., by shaping the working cathode surface and / or including one or more insulating inserts). Thus, the exemplary hybrid cathode overcomes at least some of the current limitations of the IPD process, including being beneficial for reducing costs and overcoming the problem of not being able to produce compositionally complex coatings. Additionally, the exemplary hybrid cathode is beneficial for using additional coating materials that can be used in the coating process, and thus significantly reduces the costs associated with the IPD process by allowing the operating process to be carried out for a longer period of time without replacing the cathode. Furthermore, since the cathode does not need to be replaced frequently, a more uniform and improved coating material can be deposited.

[0071] Embodiment

[0072] The following non-limiting examples further illustrate the subject matter of the present disclosure.

[0073] An attempt was made to prepare a monolithic cathode for depositing a Nb-Si-Ti-Al-Hf alloy coating containing various atomic percentages of niobium (Nb), silicon (Si), titanium (Ti), aluminum (Al), and hafnium (Hf) by mixing the elements in their respective amounts and casting the cathode. The solid material was too brittle and fragmented into multiple pieces during casting. The solid material also could not withstand the mechanical stress during machining and could not be machined into a suitable size and shape without cracking and splitting.

[0074] Thus, a hybrid cathode having a desired chemical composition capable of depositing an Nb—Si—Ti—Al—Hf alloy coating is prepared by casting a body of a Ti—Al—Si alloy cathode, the Ti—Al—Si alloy comprising about 18 atomic % to about 22 atomic % Si, about 18 atomic % to about 22 atomic % Ti, and about 58 atomic % to about 62 atomic % Al, which provides suitable solid strength and ductility for casting and machining the cathode body. An insert made of 100 atomic % p-doped Si and an Nb—Si—Ti—Hf alloy is obtained, and the insert also has suitable strength and ductility to prevent insert failure, the Nb—Si—Ti—Hf alloy comprising about 35 atomic % to about 38 atomic % Nb, about 11 atomic % to about 15 atomic % Si, about 33 atomic % to about 37 atomic % Ti, and about 14 atomic % to about 17 atomic % Hf. The Si and Nb—Si—Ti—Hf alloy inserts are forced into openings machined in the working surface of the Ti—Al—Si alloy cathode body, and the inserts are partially exposed at the working surface. An insulating insert made of boron nitride (BN) is also obtained, and the insulating insert is forced into a corresponding opening formed in a radially central region of the working surface of the Ti—Al—Si alloy cathode body. The Si and Nb—Si—Ti—Hf alloy inserts are circumferentially positioned around the insulating BN insert such that a cathode arc can move toward the Si and Nb—Si—Ti—Hf alloy inserts while avoiding the BN insert at the working surface during operation of the hybrid cathode. Thereby, the hybrid cathode is fabricated to include the necessary chemical composition for depositing a desired Nb—Si—Ti—Al—Hf alloy coating in a single hybrid cathode while reducing the tendency for cathode failure.

[0075] Other aspects of the disclosure are provided by the subject matter of the following clauses:

[0076] Clause 1. A cathode for use in an ion deposition process, the cathode comprising: a body defining a working surface of the cathode, the body comprising a first deposition material; and at least one insert coupled to the body, wherein the at least one insert is at least partially exposed at the working cathode surface, and wherein the at least one insert comprises a second deposition material incompatible with the first deposition material; wherein the first deposition material and the second deposition material are capable of being evaporated in response to an arc generated at the working cathode surface for depositing a coating comprising the first deposition material and the second deposition material on a substrate.

[0077] Clause 2. The cathode of clause 1, wherein the at least one insert comprises at least two inserts coupled to the body, wherein each insert is at least partially exposed at the working cathode surface.

[0078] Clause 3. The cathode according to Clause 2, wherein the at least two inserts are arranged such that the exposed portions of the inserts are circumferentially spaced apart at the working cathode surface.

[0079] Clause 4. The cathode according to Clause 2 or Clause 3, wherein the at least two inserts include a first insert containing the second deposition material and a second insert containing a third deposition material different from the second deposition material and incompatible with the first deposition material.

[0080] Clause 5. The cathode according to Clause 2 or Clause 3, wherein the at least two inserts include a first insert containing the second deposition material and a second insert containing a third deposition material incompatible with one of the first deposition material and the second deposition material.

[0081] Clause 6. The cathode according to any one of Clauses 2 to 5, wherein the at least two inserts include an insulating insert containing an insulating material, the insulating insert being configured to facilitate controlling the movement of the arc generated at the working cathode surface.

[0082] Clause 7. The cathode according to Clause 6, wherein the insulating material includes one of alumina and boron nitride.

[0083] Clause 8. The cathode according to any one of the preceding clauses, wherein the first deposition material includes at least one element selected from the group consisting of nickel, aluminum, cobalt, chromium, molybdenum, tungsten, rhenium, ruthenium, zirconium, hafnium, tantalum, silicon, yttrium, titanium, lanthanum, cerium, niobium, vanadium, platinum, iridium, osmium, palladium, rhodium, carbon, and boron.

[0084] Clause 9. The cathode according to any one of the preceding clauses, wherein the second deposition material includes at least one element selected from the group consisting of nickel, aluminum, cobalt, chromium, molybdenum, tungsten, rhenium, ruthenium, zirconium, hafnium, tantalum, silicon, yttrium, titanium, lanthanum, cerium, niobium, vanadium, platinum, iridium, osmium, palladium, rhodium, carbon, and boron.

[0085] Clause 10. The cathode according to any one of the preceding clauses, wherein each insert is held in a corresponding opening formed in the body of the cathode.

[0086] Clause 11. The cathode according to Clause 10, wherein each insert is held in the corresponding opening by at least one of friction fit and threaded engagement.

[0087] Clause 12. An apparatus for depositing a coating on a substrate, the apparatus comprising: a deposition chamber sized to receive the substrate therein; a cathode positioned within the deposition chamber, the cathode comprising: a body defining a working surface of the cathode, the body containing a first deposition material; at least one deposition insert coupled to the body, wherein the at least one deposition insert is at least partially exposed at the working cathode surface, and wherein the at least one deposition insert contains a second deposition material incompatible with the first deposition material; and a power supply coupled to the cathode, wherein the power supply is operable to generate an arc at the working cathode surface for evaporating the first deposition material and the second deposition material and depositing the coating containing the first deposition material and the second deposition material on the substrate.

[0088] Clause 13. The apparatus according to Clause 12, wherein the cathode further comprises an insulating insert coupled to the body and at least partially exposed at the working cathode surface, wherein the exposed portion of the insulating insert is positioned to facilitate control of the movement of the arc at the working cathode surface.

[0089] Clause 14. The apparatus according to Clause 13, wherein the exposed portion of the insulating insert is positioned in a central region of the working cathode surface to facilitate control of the circumferential movement of the arc at the working cathode surface.

[0090] Clause 15. The apparatus according to Clause 14, wherein the at least one deposition insert comprises at least two deposition inserts coupled to the body, wherein each deposition insert is at least partially exposed at the working cathode surface at a position radially outside the exposed portion of the insulating insert.

[0091] Clause 16. The apparatus according to Clause 15, wherein the at least two deposition inserts comprise a first deposition insert containing the second deposition material and a second deposition insert containing a third deposition material different from the second deposition material.

[0092] Clause 17. The apparatus according to Clause 16, wherein the third deposition material is incompatible with at least one of the first deposition material and the second deposition material.

[0093] Clause 18. A method of depositing a coating on a substrate, the method comprising: providing a cathode including a body defining a working surface of the cathode, wherein the body comprises a first deposition material; coupling at least one insert to the body such that the at least one insert is at least partially exposed at the working cathode surface, wherein the at least one insert comprises a second deposition material incompatible with the first deposition material; generating an arc at the working cathode surface to evaporate the first deposition material and the second deposition material; and depositing the evaporated first deposition material and second deposition material on the substrate.

[0094] Clause 19. The method according to Clause 18, wherein coupling the at least one insert to the body comprises: forming a corresponding opening in the working cathode surface for each insert; and positioning each insert in the corresponding opening such that each insert is retained in the corresponding opening by at least one of a friction fit and a threaded engagement.

[0095] Clause 20. The method according to Clause 18, the method further comprising: coupling an insulating insert to the body such that the insulating insert is at least partially exposed at the working cathode surface; and using the insulating insert to control the movement of the arc at the working cathode surface.

[0096] Exemplary embodiments of an ion plasma deposition system and method for depositing a coating material on a substrate using a hybrid cathode have been described in detail above. These systems and methods are not limited to the specific embodiments described herein, but rather the components of the system and / or the steps of the method can be used independently and separately from the other components and / or steps described herein. For example, these systems and methods can also be used in combination with many types of components and are not limited to being practiced only with components of a rotary machine (e.g., a gas turbine engine) as described herein. Instead, the exemplary embodiments can be implemented and utilized in conjunction with many other ion plasma deposition applications or applications involving depositing a coating material from incompatible materials.

[0097] Although specific features of various embodiments of the present disclosure may be shown in some figures and not in others, this is for convenience only. References to "one embodiment" in the above description do not exclude the existence of additional embodiments that also incorporate the recited features. In accordance with the principles of the embodiments of the present disclosure, any feature of any figure can be referenced and / or claimed in combination with any feature of any other figure.

[0098] This written description uses examples to disclose embodiments of the present disclosure, including the best mode, and also enables any person skilled in the art to practice the embodiments of the present disclosure, including making and using any device or system and performing any combined method. The patentable scope of the embodiments described herein is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements that do not differ materially from the literal language of the claims.

Claims

1. A cathode (200) for use in an ion deposition process, the cathode comprising: A body (202) that defines a working surface (204) of the cathode, the body comprising a first deposition material; And At least one insert (218) coupled to the body, wherein the at least one insert is at least partially exposed at the working cathode surface, and wherein the at least one insert comprises a second deposition material incompatible with the first deposition material; Wherein the first deposition material and the second deposition material are capable of evaporating in response to an arc generated at the working cathode surface for depositing a coating comprising the first deposition material and the second deposition material on a substrate (108).

2. The cathode (200) according to claim 1, wherein the at least one insert (218) comprises at least two inserts coupled to the body (202), wherein each insert is at least partially exposed at the working cathode surface (204).

3. The cathode (200) according to claim 2, wherein: The at least two inserts are arranged such that the exposed portions (220) of the inserts (218) are circumferentially spaced apart at the working cathode surface (204); and / or The at least two inserts comprise a first insert comprising the second deposition material and a second insert comprising a third deposition material, optionally wherein the third deposition material is different from the second deposition material and / or incompatible with one of the first deposition material and the second deposition material; And / or The at least two inserts comprise an insulating insert (224) comprising an insulating material configured to facilitate controlling the movement of the arc generated at the working cathode surface, optionally wherein the insulating material comprises one of alumina and boron nitride.

4. The cathode (200) according to any one of claims 1 to 3, wherein the first deposition material comprises at least one element selected from the group consisting of nickel, aluminum, cobalt, chromium, molybdenum, tungsten, rhenium, ruthenium, zirconium, hafnium, tantalum, silicon, yttrium, titanium, lanthanum, cerium, niobium, vanadium, platinum, iridium, osmium, palladium, rhodium, carbon, and boron.

5. The cathode (200) according to any one of claims 1 to 4, wherein the second deposition material comprises at least one element selected from the group consisting of nickel, aluminum, cobalt, chromium, molybdenum, tungsten, rhenium, ruthenium, zirconium, hafnium, tantalum, silicon, yttrium, titanium, lanthanum, cerium, niobium, vanadium, platinum, iridium, osmium, palladium, rhodium, carbon, and boron.

6. The cathode (200) according to any one of claims 1 to 5, wherein each insert (218) is held in a corresponding opening (216) formed in the body (202) of the cathode, optionally wherein each insert is held in the corresponding opening by at least one of a friction fit and a threaded engagement.

7. An apparatus (100) for depositing a coating on a substrate (108), the apparatus comprising: A deposition chamber (102) sized to receive the substrate therein; A cathode (200) positioned within the deposition chamber, the cathode comprising: a body (202) defining a working surface (204) of the cathode, the body comprising a first deposition material; at least one deposition insert (218) coupled to the body, wherein the at least one deposition insert is at least partially exposed at the working cathode surface and wherein the at least one deposition insert comprises a second deposition material incompatible with the first deposition material; and a power supply (114) coupled to the cathode, wherein the power supply is operable to generate an arc at the working cathode surface for evaporating the first deposition material and the second deposition material and depositing the coating comprising the first deposition material and the second deposition material on the substrate.

8. The apparatus (100) of claim 7, wherein the cathode further comprises an insulating insert (224) coupled to the body (202) and at least partially exposed at the working cathode surface (204), wherein the exposed portion (226) of the insulating insert is positioned to facilitate control of movement of the arc at the working cathode surface.

9. The apparatus (100) of claim 8, wherein the exposed portion (220) of the insulating insert (218) is positioned in a central region of the working cathode surface (204) to facilitate control of circumferential movement of the arc at the working cathode surface.

10. The apparatus (100) of claim 9, wherein the at least one deposition insert (218) comprises at least two deposition inserts coupled to the body (202), wherein each deposition insert is at least partially exposed at the working cathode surface (204) at a position radially outside the exposed portion (226) of the insulating insert (224).

11. The apparatus (100) of claim 10, wherein the at least two deposition inserts (218) comprise a first deposition insert comprising the second deposition material and a second deposition insert comprising a third deposition material different from the second deposition material.

12. The apparatus (100) of claim 11, wherein the third deposition material is incompatible with at least one of the first deposition material and the second deposition material.

13. A method (300) of depositing a coating on a substrate, the method comprising: providing (302) a cathode comprising a body defining a working surface of the cathode, wherein the body comprises a first deposition material; coupling (304) at least one insert to the body such that the at least one insert is at least partially exposed at the working cathode surface, wherein the at least one insert comprises a second deposition material incompatible with the first deposition material; generating (306) an arc at the working cathode surface to evaporate the first deposition material and the second deposition material; and Deposit (308) the evaporated first deposition material and second deposition material on a substrate.

14. The method (300) according to claim 13, wherein coupling (304) the at least one insert to the body comprises: Forming a corresponding opening in the working cathode surface for each insert; And Positioning each insert in the corresponding opening such that each insert is retained in the corresponding opening by at least one of a friction fit and a threaded engagement.

15. The method (300) according to claim 13, the method further comprising: Coupling an insulating insert to the body such that the insulating insert is at least partially exposed at the working cathode surface; And Using the insulating insert to control movement of the arc at the working cathode surface.

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