Method for producing beryllium-based articles

Abstract

A method for manufacturing a beryllium-based article object containing beryllium by depositing a layer of beryllium, wherein an element is added to the beryllium, which dissolves and forms a secondary phase, limiting the columnar grain size. The grain refinement allows the beryllium article to have beneficial properties with respect to strength and durability.

Description

[Technical Field]

[0001] Priority claims

[0001] This application claims priority to U.S. Provisional Patent Application No. 63 / 409,101, filed September 22, 2022, which is incorporated herein by reference in its entirety.

[0002] This disclosure relates to methods of manufacturing beryllium-based articles. In particular, the methods involve adding elements that dissolve in molten beryllium to promote fine grain structure and limit columnar grain structure, thereby producing beryllium-based articles with improved grain structure, which leads to improved strength and workability. [Background technology]

[0003] Beryllium is a metal with highly desirable properties. These include high stiffness (Young's modulus 287 GPa), low density (1.85 g / cc), high modulus of elasticity (130 GPa), high specific heat (1925 J / kg·K), high thermal conductivity (216 W / m·K), and a low coefficient of linear thermal expansion (11.4×10 6 / K). As a result, beryllium and its composites are useful in aerospace structures, high performance engines and brakes, and electronic components for thermal performance and vibration damping. Beryllium and its composites are also useful in several different applications, including combustion applications, hypersonic vehicles, computer components, optics for space and ground-based systems, satellite structures, solar energy collectors, and nuclear energy amplification applications.

[0004] One limitation is that casting methods are not suitable for producing beryllium products, resulting in cylindrical solidification. Beryllium is a highly reactive metal with a high melting point and susceptible to reaction with mold wall materials, forming beryllium compounds (BeO and others) that become trapped in the solidified metal. In addition, grain sizes exceed 500 microns, typically significantly larger than this, up to 50,000 microns. This is too large to meet strength requirements, making the material brittle. Further attempts to refine the grain size through mechanical work have not met commercial success. To overcome the problems of beryllium production, beryllium powder has been used. Beryllium powder may be formed by ball milling, disk grinding, or gas atomization processes. The powder is consolidated into ingots, which may be further processed into beryllium molding components. This process requires careful handling of the beryllium powder. Additionally, powder processes have low material utilization, leading to inefficiencies and increased costs. Powder processes are also limited in forming complex shapes.

[0005]

[0005] Objects built by depositing layers can have complex shapes, but they still suffer from poor crystalline structure due to the lack of plastic deformation from mechanical forming. Because the layers are built unidirectionally, solidification tends to result in a poor microstructure, with columnar grains predominating. This undesirable reduction in mechanical properties results in a loss of strength and durability. Summary of the Invention [Problem to be solved by the invention]

[0006]

[0006] There remains a need to eliminate columnar solidification in order to produce beryllium-based articles having reduced grain size in an efficient manner. [Means for solving the problem]

[0007]

[0007] The present disclosure provides a method for producing beryllium-based articles in which elements such as aluminum, silicon, and / or silver are added to the beryllium powder. The elements added to the beryllium powder can affect thermal activity. When the elements are added, they change the behavior of the molten pool, resulting in a fine grain structure with a constrained columnar structure. Improvements can be achieved in the strength and durability of beryllium-based articles, including those produced with complex three-dimensional shapes.

[0008] In one embodiment, a method is provided that includes a layer comprising beryllium powder and elements such as aluminum, silicon, and / or silver that can be deposited on a surface, and energy can be applied to at least a portion of the layer, for example, from a laser or electron beam, to form molten beryllium in which at least a portion of the elements have dissolved. The molten beryllium can then be solidified to form secondary phases from the dissolved elements, and the process of deposition, heating, and solidification can be repeated over successive layers to form a beryllium-based article. In one embodiment, the secondary phases can be dispersed among the beryllium grains. In one embodiment, the beryllium has an average grain size of 1 to 80 microns.

[0009] In one embodiment, a method for producing a beryllium-based article is provided, comprising the steps of: adding an element and a nucleating agent to beryllium powder; depositing a layer containing the beryllium powder on a surface; applying energy to at least a portion of the layer to form molten beryllium, with at least a portion of the element dissolved in the molten beryllium; solidifying the molten beryllium, with the beryllium having an average grain size of 1 to 80 microns; and repeating the deposition / application / solidification steps for successive layers to form the beryllium-based article. In one embodiment, the element is effective in limiting growth and isolating the nucleating agent. Preferably, the nucleating agent may include beryllium titanium, beryllium chromium, iron beryllium, beryllium zirconium, tantalum beryllide, beryllium molybdenum, niobium beryllium, beryllium tungsten, beryllium strontium, and / or beryllium hafnium.

[0010]

[0010] These and other non-limiting features are more particularly described below. DETAILED DESCRIPTION OF THE INVENTION

[0011]

[0011] The present disclosure may be more readily understood by reference to the following detailed description of the preferred embodiment and examples contained therein. In the following specification and in the claims that follow, reference will be made to a number of terms which shall be defined to have the following meanings:

[0012]

[0012] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. In the case of conflict, the present document, including definitions, will control. Preferred methods and materials are described below, although methods and materials similar or equivalent to those described herein may be used in the practice or testing of this disclosure. All publications, patent applications, patents, and other references mentioned herein are incorporated by reference in their entirety. The materials, methods, and examples disclosed herein are illustrative only and are not intended to be limiting.

[0013]

[0013] The singular forms "a," "an," and "the" include plural references unless the context clearly dictates otherwise.

[0014] As used in this specification and claims, the term "comprising" can include the embodiments "consisting of" and "consisting essentially of." The terms "comprise," "include," "having," "has," "can," "contain," and variations thereof, as used herein, are intended to be open-ended transitional phrases that require the presence of the named ingredients / steps and allow for the presence of other materials / steps. However, such statements should also be construed as describing a composition or method as "consisting of" and "consisting essentially of" the recited ingredients / steps, which allows for the presence of only the recited ingredients / steps, along with any impurities that may result from them, and excludes other ingredients / steps.

[0014]

[0015] Numerical values ​​in this specification and in the claims of this application, when they relate to compositions, articles, or powders, reflect average values ​​for compositions that may contain individual polymers with different characteristics. Numerical values ​​disclosed herein include numerical values ​​that are identical when rounded to the same number of significant figures, and that do not differ from the stated value by more than experimental error using conventional measurement techniques of the type described in this application to determine the value.

[0015]

[0016] All ranges disclosed herein are inclusive of the recited endpoints and are independently combinable (e.g., the range "1 micron to 80 microns" includes the endpoints 1 micron and 80 microns, and all intermediate values). The endpoints of the ranges and any values ​​disclosed herein are not limited to the exact ranges or values, as they are sufficiently imprecise to include values ​​that approximate those ranges and / or values.

[0016]

[0017] As used herein, approximating words can be used to modify any quantitative expression, which can vary without resulting in a change in the basic function to which it pertains. Thus, values ​​modified by terms such as "about" and "substantially" may in some cases not be limited to the exact value specified. The modifier "about" should also be considered to disclose a range defined by the absolute values ​​of the two endpoints. For example, the expression "about 2 to about 4" also discloses the range "2 to 4." The term "about" can refer to plus or minus 10% of the indicated number. For example, "about 10%" can indicate a range of 9% to 11%, and "about 1" can mean 0.9 to 1.1.

[0017]

[0018] For the recitation of ranges of numbers herein, each intervening number is expressly contemplated with the same precision. For example, for the range 6 to 9, the numbers 7 and 8 are contemplated in addition to 6 and 9, and for the range 6.0 to 7.0, the numbers 6.0, 6.1, 6.2, 6.3, 6.4, 6.5, 6.6, 6.7, 6.8, 6.9, and 7.0 are expressly contemplated.

[0018]

[0019] As described herein, there is a method for producing a beryllium-based article. The process involves adding an element to a beryllium powder, preferably an element that is at least partially soluble in the molten beryllium. The presence of the element or solute in the molten beryllium can affect grain refinement by slowing solid growth and aiding in the segregation of nucleating agents. This mechanism results in enrichment of the solute near the solidification interface. For purposes of this disclosure, elements include aluminum, silicon, and / or silver. During solidification of the molten beryllium, the dissolved element may promote the formation of a secondary phase. In one embodiment, the secondary phase can promote a fine grain size while beneficially limiting columnar structures. Without being bound by theory, the presence of an at least partially dissolved element may contribute to grain refinement of the beryllium-based article.

[0019]

[0020] As used herein, the term "dissolve" means that the element is solubilized in the molten beryllium to form a homogeneous solution.

[0021] In one embodiment, the beryllium-based article is fabricated through a series of layers, each layer being fabricated by applying energy to beryllium powder followed by solidification. In one embodiment, an element can be added to the beryllium powder deposited on a surface, and the beryllium powder can be heated by applying energy thereto to produce molten beryllium, with at least a portion of the element dissolved in the molten beryllium. In one embodiment, the element is completely dissolved in the molten beryllium.

[0020]

[0022] Undissolved portions of elements may provide nucleation sites, while dissolved portions may redistribute during solidification. In one embodiment, molten beryllium can solidify to form secondary phases from the dissolved elements. In one embodiment, the secondary phases may be dispersed among the beryllium grains after successive depositions / applications / solidifications. The aforementioned grain refinement of beryllium-based articles can lead to improved strength and processability when forming articles with a series of layers. In one embodiment, the beryllium-based article can have an average grain size of 1 to 80 microns, e.g., 1 to 75 microns, 1 to 60 microns, 1 to 50 microns, 1 to 40 microns, 5 to 40 microns, 5 to 25 microns, 5 to 15 microns, or 10 to 15 microns. In one embodiment, a portion of the grains of the beryllium-based article can have an aspect ratio of less than 3:1. In particular, at least 75% of the grains of the beryllium-based article can have an aspect ratio of less than 3:1, e.g., less than 2.5:1 or less than 2:1. The average grain size and aspect ratio can be determined using optical imaging, such as SEM imaging, and by comparison, area measurement, or using the intercept parameter of ASTM E 112-12.

[0021]

[0023] Elements with significant growth limiting factors are useful for grain refinement to slow beryllium grain growth. In one embodiment, aluminum, silicon, silver, and / or combinations thereof are efficient solutes for grain refinement. A sufficient amount of the element is added to achieve the desired grain refinement. In one embodiment, the element comprises 0.1 wt.% to 25 wt.%, e.g., 0.1 wt.% to 20 wt.%, 0.25 wt.% to 15 wt.%, 0.25 wt.% to 10 wt.%, 0.25 wt.% to 5 wt.%, 0.5 wt.% to 5 wt.%, or 0.5 wt.% to 1.5 wt.%, of the total weight of the beryllium-based article. If the amount of the element exceeds 25 wt.%, the element tends to become less soluble.

[0022]

[0024] The element may be added to the beryllium powder. In one embodiment, a portion of the element may bond to the surface of the beryllium powder. Preferably, the element does not react with the beryllium powder while being added.

[0023]

[0025] In one embodiment, the secondary phase forms from the elements as the molten beryllium solidifies, hi one embodiment, the secondary phase is dispersed among the beryllium grains after the molten beryllium solidifies.

[0024]

[0026] In one embodiment, the elements added to the beryllium powder include metals that provide nucleation sites for beryllium. The elements disclosed herein can affect nucleation through interface segregation and growth restriction, which can affect grain refinement. The elements can be present as loose powders, pastes, or suspensions that can be combined with the beryllium. In one embodiment, the elements remain unreacted when combined with the beryllium powder. Elements can be added to the beryllium powder by several techniques, including mixing, blending, atomization, mechanical alloying, resonance mixing, or combinations thereof. Resonance mixing is useful for achieving thorough mixing when adding elements to beryllium powders of different sizes. In one embodiment, resonance mixing induces non-contact acoustic mixing with sound waves at frequencies between 20 and 80 Hz, achieving good mixing in a short time without inducing fragmentation or stress in the beryllium powder. In one embodiment, the elements include silver, aluminum, silicon, and / or combinations thereof.

[0025]

[0027] In one embodiment, the element-containing beryllium powder is deposited as a layer, eliminating the need for a prior deposition addition step. Accordingly, there is provided a method for producing a beryllium-based article, comprising the steps of depositing a layer on a surface comprising beryllium powder containing an element selected from the group consisting of silver, silicon, and aluminum; thermally cycling at least a portion of the layer above a temperature required to form molten beryllium; solidifying the layer; and repeating the deposition / thermal cycling / solidification steps for successive layers, each of which comprises beryllium powder. Preferably, the beryllium-based article has an average grain size of 1 to 80 microns.

[0026]

[0028] In one embodiment, the element can be a metal powder. The metal powder can have an aspect ratio (average length to average width) of 1:1 to 100:1, e.g., 1:1 to 50:1, 1:1 to 20:1, 1:1 to 10:1, or 1:1 to 5:1. The metal powder can be smaller than beryllium powder. The metal powder can have an average diameter (D) of 10 microns or less, e.g., less than 8 microns, less than 5 microns, less than 2.5 microns, less than 2 microns, or less than 1 micron. 50 In some embodiments, the metal powder may have an average (D ) particle size that is nanoparticles, e.g., less than 1 micron. 50 In some embodiments, the nanoparticles may have an average diameter (D) of 10 to 1000 nanometers, e.g., 25 to 950 nanometers, 50 to 900 nanometers, 100 to 800 nanometers, or 300 to 700 nanometers. 50 Thus, the metal powder may have an average (D 50 ) particle size.

[0027]

[0029] In one embodiment, the beryllium powder may include beryllium. Various amounts of beryllium may be suitable for the embodiments disclosed herein. In one exemplary embodiment, the beryllium powder includes greater than 40% by weight of beryllium. In one embodiment, the beryllium powder may include 40% to 95% by weight of beryllium. More preferably, the beryllium powder may include 50% to 95% by weight of beryllium, e.g., 60% to 95% by weight or 80% to 95% by weight of beryllium.

[0028]

[0030] In another embodiment, the beryllium powder can be S-65 grade (minimum Be content 99.2%, maximum BeO 0.9%), S-200 (minimum Be content 98.5%), 0-30 (isostatically pressed beryllium, minimum Be content 99%, maximum BeO 0.5%), and all available from Materion Corporation. The beryllium powder can have an aspect ratio (average length to average width) of 1:1 to 100:1, e.g., 1:1 to 50:1, 1:1 to 20:1, 1:1 to 10:1, or 1:1 to 5:1. In one embodiment, the beryllium powder can be spherical in shape. The beryllium powder can have an average diameter (D) of 1 micron to 200 microns, e.g., 5 microns to 175 microns, 10 microns to 150 microns, 15 microns to 100 microns, 25 microns to 70 microns, or 25 microns to 50 microns. 50 ) particle size. 50 , i.e., the diameter at which a cumulative percentage of 50% of the particles reach by volume. Powders smaller than 200 microns may be constructively used to form beryllium-based articles with reduced grain refinement. If required, the beryllium powder may be sieved to achieve the desired particle size.

[0029]

[0031] In one embodiment, the beryllium powder can be in the form of particles having a core-shell structure, with the beryllium constituting the core and a continuous or semi-continuous coating constituting the shell. The beryllium coating can be achieved by ball milling, resonance mixing, spray bonding, spray drying, laser ablation, electro-discharge machining, and atomic layer deposition. In some embodiments, the coating comprises nickel, either pure nickel or a nickel alloy. The core can comprise 0.1 wt% to 99.9 wt%, or 50 wt% to 99.9 wt%, or about 92 wt% to less than 100 wt% of the particle. In some embodiments, the coating can comprise 0.1 wt% to 99.9 wt%, or 0.1 wt% to 50 wt%, or greater than zero wt% to about 8 wt% nickel. In certain embodiments, the beryllium powder comprises about 92 wt% to less than 100 wt% beryllium and greater than zero wt% to about 8 wt% nickel. Generally, it is contemplated that the coating will form particles for grain refinement.

[0030]

[0032] In one embodiment, the beryllium powder may have at least a portion of the element bonded to the surface of the beryllium powder.

[0033] The element can be combined with the beryllium powder in an effective amount to promote fine grain size and limit columnar structure. In one embodiment, the amount of the element combined with the beryllium powder can be 0.1 to 25 wt % based on the total weight of the beryllium powder. More preferably, the element can be present in an amount of 0.1 to 10 wt %, e.g., 0.25 to 10 wt %, 0.25 to 8 wt %, 0.5 to 5 wt %, or 0.5 to 1.5 wt %.

[0031]

[0034] In one embodiment, the element is silver, and is added to the beryllium powder in an effective amount to promote fine grain size and limit columnar structure. Silver is effective in grain refinement and can produce articles with improved strength and performance. In one embodiment, the silver can be present in the beryllium powder in an amount of 0.1 to 25 wt %, based on the total weight of the beryllium powder. More preferably, the silver can be present in an amount of 0.1 to 10 wt %, e.g., 0.25 to 10 wt %, 0.25 to 8 wt %, 0.5 to 5 wt %, or 0.5 to 1.5 wt %.

[0032]

[0035] In one embodiment, the element is aluminum, combined with beryllium in an effective amount to promote a fine grain size and limit columnar structure. Aluminum is effective in grain refinement, which can produce articles with improved strength and performance. In one embodiment, aluminum can be present in the beryllium powder in an amount of 0.1 to 25 wt. % based on the total weight of the beryllium powder. More preferably, aluminum can be present in an amount of 0.1 to 10 wt. %, e.g., 0.25 to 10 wt. %, 0.25 to 8 wt. %, 0.5 to 5 wt. %, or 0.5 to 1.5 wt. %.

[0033]

[0036] In one embodiment, the element is silicon, which can be combined with beryllium in an effective amount to promote a fine grain size and limit columnar structure. Silicon is effective in grain refinement and can produce articles with improved strength and performance. In one embodiment, silicon can be present in the beryllium powder in an amount of 0.1 to 25 wt. % based on the total weight of the beryllium powder. More preferably, silicon can be present in an amount of 0.1 to 10 wt. %, e.g., 0.25 to 10 wt. %, 0.25 to 8 wt. %, 0.5 to 5 wt. %, or 0.5 to 1.5 wt. %.

[0034]

[0037] In one embodiment, the elements are a combination of silver, silicon, and / or aluminum, combined with beryllium in an effective amount to promote fine grain size and limit columnar structure. The combination of silver, silicon, and / or aluminum is effective for grain refinement and can produce articles with improved strength and performance. In one embodiment, the combined silver, silicon, and / or aluminum can be present in the beryllium powder in an amount of 0.1 to 25 wt %, based on the total weight of the beryllium powder. More preferably, the combined silver, silicon, and / or aluminum can be present in an amount of 0.1 to 10 wt %, e.g., 0.25 to 10 wt %, 0.25 to 8 wt %, 0.5 to 5 wt %, or 0.5 to 1.5 wt %.

[0035]

[0038] The beryllium powder may include a nucleating agent for grain refinement. In one embodiment, the beryllium powder may include a beryllium intermetallic compound that functions as a nucleating agent. In one embodiment, the beryllium intermetallic compound is beryllium titanium (Be 12 Ti, Be2Ti), Beryllium Chromium (Be2Cr or Be 12 Cr), iron beryllium (FeBe5), beryllium zirconium (Be 13 Zr, Be5Zr, Zr2Be 17 ), tantalum beryllide (TaBe2, Ta2Be 17 ,TaBe 12 or TaBe 17 ), Beryllium Molybdenum (Be2Mo, Be 12 Mo, Be 22 Mo), niobium beryllium (NbBe2, NbBe3, Nb2Be 17 , NbBe 12 ), Beryllium Tungsten (Be 22 W), Beryllium Strontium (Be 13Sr), and / or beryllium hafnium (Be5Hf). As particles are formed, the nucleation energy of the beryllium is reduced, and grain refinement is achieved. Without limitation, the nucleating agent may be present in an amount of 0-40 wt%, e.g., 0-35 wt%, 0-30 wt%, 0.5-35 wt%, 1-30 wt%, or 1-20 wt%, based on the total weight of the beryllium powder.

[0036]

[0039] In one embodiment, the beryllium powder can be in the form of particles, such as a powder, having a D50 average particle size of 10 to 50 microns, e.g., 15 to 50 microns, 20 to 45 microns, or 25 to 40 microns.

[0037]

[0040] method

[0041] Beryllium-based articles can be formed by thermally cycling several layers of deposited beryllium powder. After applying energy to form molten beryllium, added elements in the beryllium powder can at least partially dissolve therein and form secondary phases upon solidification. In one embodiment, complex shapes can be formed from articles having multiple layers. In one embodiment, the resulting shape can be a geometric or three-dimensional shape formed from multiple layers. In one embodiment, the method deposits the first layer, preferably at a relatively high rate. In one embodiment, the first layer can be uniformly deposited by depositing beryllium powder on the surface of a substrate. In some embodiments, the first layer can be deposited on a surface such as a substrate, base, or substrate.

[0038]

[0042] The process can begin by depositing the first layer in a build box. Preferably, the beryllium powder to be doped is transferred to the build box with minimal loss or contamination of the surrounding area. The build box includes a surface, e.g., a build base, and sidewalls. The build base is a generally flat surface upon which successive layers are deposited. The build base can move along a vertical z-axis based on signals from a computerized controller. The sidewalls cooperate with the build base to form a "box" that contains the deposited beryllium powder. Typically, the sidewalls remain in a fixed position while the build base moves downward to allow the next layer of beryllium powder to be deposited.

[0039]

[0043] The initial layer can be deposited on a surface in a predetermined pattern. In some embodiments, the preset pattern is determined based on a computer-aided design (CAD) layer. Any suitable technique for depositing the initial layer is suitable for the method, including spreading, painting, brushing, rolling, spraying, or dispensing. In one embodiment, one or more deposition heads are used to move in a horizontal xy plane. A controller can be used to move the one or more deposition heads specified by the design. The horizontal xy plane is the plane defined by the x-axis and y-axis, where the x-axis, y-axis, and z-axis are mutually orthogonal.

[0040]

[0044] In some embodiments, deposition occurs under an inert gas atmosphere. In one embodiment, deposition can occur in a reducing atmosphere to reduce oxide formation. After the beryllium powder phase is deposited, energy can be applied in the reducing atmosphere. In one embodiment, the reducing atmosphere contains 20 vol.% or less of oxygen, e.g., less than 15 vol.%, less than 10 vol.%, or less than 5 vol.%.

[0041]

[0045] In one embodiment, each layer can be deposited in a uniform manner. The initial layer can have a thickness of 20 to 200 microns, e.g., 25 to 150 microns, 25 to 110 microns, 30 to 100 microns, 35 to 75 microns, or 40 to 60 microns. In some embodiments, the layers can be formed by compressing the deposited beryllium powder using any suitable compression method. Compressing the powder may be desirable to provide a thin layer, using a mechanical compactor such as a doctor blade, double rolling, or electrostatic force.

[0042]

[0046] Following deposition of the initial layer, the process employs a thermal cycling process that heats the initial layer to a temperature sufficient to form molten beryllium, and then cools the layer thereafter. In one embodiment, the thermal cycling process can be rapid to increase productivity and efficiency. In one embodiment, the thermal cycling further includes exposing the deposited initial layer to an energy source. The thermal cycling rapidly transitions through a thermal gradient to solidify the beryllium-based article. In one embodiment, the energy source can be directed at at least a portion of the initial layer. The energy source can generate localized or focused energy to heat at least a portion of the initial layer, preferably to heat at least a portion of the initial layer. The energy source can be an electron beam or a laser beam, and can be 10 3 W / mm 2 ~10 7 W / mm 2 , e.g. 10 4 W / mm 2 ~10 7 W / mm 2 , or 10 5 W / mm 2 ~10 6 W / mm 2 It has a power density of 10 7 W / mm 2Operating the energy source at less than 1000 W power is sufficient to generate heat above a temperature sufficient to form molten beryllium. In one embodiment, the effective diameter of the energy source can be 10 to 200 microns, e.g., 25 to 150 microns, or 35 to 100 microns. The scanning speed of the energy source can be 10 mm / s to 2000 mm / s, e.g., 50 mm / s to 1500 mm / s or 100 mm / s to 1000 mm / s. The raster width of the energy source can be 50 to 500 microns, e.g., 75 to 450 microns, 75 to 400 microns, or 100 to 350 microns. In one embodiment, the layer thickness can be 20 microns to 200 microns, e.g., 25 microns to 175 microns or 50 microns to 150 microns.

[0043]

[0047] In one embodiment, the energy source and / or another source heats the first layer to a temperature sufficient to form molten beryllium. In one embodiment, the temperature can be between 1000°C and 1500°C, e.g., between 1100°C and 1450°C, between 1200°C and 1400°C, or between 1290°C and 1325°C. In one embodiment, the thermal cycling process can be rapid to increase productivity. The thermal cycling process can last 300 seconds or less, e.g., less than 240 seconds, less than 180 seconds, less than 120 seconds, less than 90 seconds, less than 60 seconds, less than 50 seconds, less than 45 seconds, less than 30 seconds, less than 25 seconds, less than 20 seconds, less than 10 seconds, less than 5 seconds, less than 1 second, or less than 0.5 seconds. In terms of ranges, in one embodiment, the rapid thermal cycle can be 0.01 to 300 seconds, e.g., 0.01 to 240 seconds, 0.1 to 180 seconds, 0.2 to 120 seconds, 0.2 to 90 seconds, 0.25 to 60 seconds, 0.5 to 60 seconds, 0.5 to 30 seconds, 0.5 to 15 seconds, or 0.5 to 10 seconds.

[0044]

[0048] Unless preheat is used, the first layer can be deposited at room temperature (20-25°C). In some embodiments, the deposited first layer can be preheated in the build box to a temperature of at least 100°C, e.g., at least 120°C, or 150°C, at least 200°C, at least 400°C, at least 450°C, or at least 500°C.

[0045]

[0049] Performing the method under reduced pressure or vacuum may allow for quality control of the layer and beryllium-based article material. Nevertheless, in some embodiments, the method may be performed under atmospheric pressure.

[0046]

[0050] As part of the thermal cycling process, the process also cools the deposited layer. In one embodiment, the minimum cooling rate can be greater than 10°C / min, e.g., greater than 15°C / min or greater than 20°C / min. In some embodiments, to achieve solidification, the cooling rate can be greater than 1000°C / min, e.g., greater than 10,000°C / min. Cooling or undercooling can be achieved at a cooling rate between 10°C / min and 10,000°C / min, e.g., between 20°C / min and 5,000°C / min, between 50°C / min and 3,000°C / min, or between 100°C / min and 1000°C / min. In one embodiment, cooling can be in the direction of layer buildup. During solidification, secondary phases can form from dissolved elements. The secondary phases may be dispersed among the beryllium crystallites and contribute to grain refinement.

[0047]

[0051] A coolant can be used to remove excess energy applied to the layer to achieve the desired cooling. The coolant can further reduce temperature gradients within the layer that tend to form columnar grains, thereby improving grain refinement. In one embodiment, the coolant can be an inert gas such as nitrogen or a noble gas, particularly argon. The coolant can be a mixture of gases. The coolant can be delivered to the layer as a focused gas stream at temperatures below 100°C, e.g., below 75°C, below 50°C, below 25°C, below 0°C, below -10°C, below -25°C, or below -50°C. In terms of ranges, the coolant can be applied at temperatures between -200°C and 100°C, e.g., between -150°C and 50°C, or between -100°C and 25°C, including subranges thereof. The coolant flow can be adjusted as the layer is deposited, and the flow rate can be below 500 L / min, e.g., less than 250 L / min or less than 100 L / min.

[0048]

[0052] The thermal condition of the article can be monitored using an infrared temperature sensor, a thermocouple, a resistance temperature detector, a thermistor, or other suitable temperature sensor. The sensor can monitor the temperature in the area where the energy and / or coolant is applied. In response to the temperature, the process can adjust the cooling rate by adjusting the flow rate, duration, or temperature of the coolant.

[0049]

[0053] In one embodiment, the beryllium powder may be heated to a temperature sufficient to form molten beryllium. In one embodiment, at least a portion of the elements are dissolved in the molten beryllium. In one embodiment, the elements are completely dissolved in the beryllium. In one embodiment, the content of the dissolved elements is less than the total content of the elements added to the beryllium. In one embodiment, the content of the dissolved elements is less than the total content of the elements added to the beryllium. Once dissolved, the elements are freely available with respect to growth constraints.

[0050]

[0054] In one embodiment, the ratio of dissolved elements to undissolved elements is between 0.1:50 and 50:0.1, for example, 0.5:40, 1:20, 5:10, 1:1, 10:5, 20:1, 40:0.5, or 50:0.1.

[0051]

[0055] The process may continue in a similar manner for successive layers, with each layer of deposited beryllium powder being thermally cycled in this manner to solidify the molten beryllium powder in the layer. After allowing sufficient time for solidification, one or more successive layers may be deposited in a predetermined pattern on at least a portion of the opposite surface of the initial layer. Each successive layer may thereby be deposited on at least a portion of the previously deposited layer, continuing to build the beryllium-based article. In one embodiment, the successive layers are deposited to acquire a complex shape, such as a three-dimensional shape. Successive layers may be deposited at room temperature or may be preheated similarly to the initial layer. In a similar manner, an energy source is directed at at least a portion of the successive layers to thermally cycle them at a temperature sufficient to either partially or completely dissolve the elements in the molten beryllium. In one embodiment, the energy source is controlled within similar operating parameters as for the initial layer. Depending on the article, the pattern may be different for each successive layer. In some embodiments, successive layers may be deposited on at least a portion of the previous or initial layer.

[0052]

[0056] In some embodiments, the surface or build plate can be lowered by the thickness of the next successive layer. The thickness of successive layers can vary; in one embodiment, successive layers can have thicknesses of 20 to 200 microns, e.g., 25 to 150 microns, 25 to 110 microns, 30 to 100 microns, 35 to 75 microns, or 40 to 60 microns. In some embodiments, each successive layer can have a similar thickness, or the thickness can accommodate the beryllium-based article. The method can continue by repeated deposition, thermal cycling, and precipitation until the desired beryllium-based article is formed. In one embodiment, a three-dimensional object is formed. In one embodiment, the beryllium-based article can be formed using one or more successive layers, e.g., at least five successive layers, at least ten successive layers, or at least 20 successive layers. For some articles, hundreds of layers can be used, and thus the number of layers is unlimited.

[0053]

[0057] The direction of the microstructure is not limited to the build direction of successive layers. The microstructure of the beryllium-based article can contain multiple dendritic layers with different primary growth direction angles relative to each other. This results in a crack-free beryllium-based article.

[0054]

[0058] In some embodiments, the method further includes curing the multiple layers prior to sintering the preform. In one embodiment, the beryllium-based article may be solidified and subsequently quenched. The beryllium-based article may be tempered for 6 to 12 hours, e.g., 8 to 10 hours. The quenching rate may be greater than 25°C / min, e.g., greater than 50°C / min or greater than 100°C / min. The quenching may be performed gradually at room temperature. The tempered article may be finished, e.g., by polishing or plating. The surface roughness of the article may be reduced, e.g., through bead blasting or barrel finishing. In some embodiments, the produced beryllium-based article may have loose or unfused particles in one or more layers. The unfused particles may be removed by blowing or suction, if necessary.

[0055]

[0059] The present disclosure has been described with reference to exemplary embodiments. Obviously, modifications and alterations will occur to others upon reading and understanding the preceding detailed description. It is intended that the present disclosure be construed as including all such modifications and alterations insofar as they come within the scope of the appended claims or the equivalents thereof.

[0056]

[0060] As used hereinafter, any reference to a series of embodiments will be understood as a disjunctive reference to each of those embodiments (e.g., "Embodiments 1-4" will be understood as "Embodiments 1, 2, 3 or 4").

[0057]

[0061] Embodiment 1 is a method of making a beryllium-based article, the method including the steps of adding an element and a nucleating agent to beryllium powder; depositing a layer including the beryllium powder on a surface; applying energy to at least a portion of the layer to form molten beryllium, wherein at least a portion of the element is dissolved in the molten beryllium; solidifying the molten beryllium, wherein the beryllium has an average grain size of 1 to 80 microns; and repeating the depositing / applying / solidifying steps for successive layers to form the beryllium-based article.

[0058]

[0062] Embodiment 2 is an embodiment of embodiment 1, wherein the nucleating agent comprises beryllium titanium, beryllium chromium, iron beryllium, beryllium zirconium, tantalum beryllide, beryllium molybdenum, niobium beryllium, beryllium tungsten, beryllium strontium, and / or beryllium hafnium.

[0059]

[0063] Embodiment 3 is an embodiment of embodiment 1, wherein the beryllium powder comprises 0-40 wt % of a nucleating agent.

[0064] Embodiment 4 is a method of making a beryllium-based article, the method including the steps of: adding elements to beryllium powder; depositing a layer including the beryllium powder on a surface; applying energy to at least a portion of the layer to form molten beryllium, wherein at least a portion of the elements are dissolved in the molten beryllium; solidifying the molten beryllium to form a secondary phase from the dissolved elements; and repeating the depositing / applying / solidifying steps for successive layers to form the beryllium-based article.

[0060]

[0065] Embodiment 5 is any one of embodiments 1 to 4, wherein the element comprises aluminum, silicon, or silver.

[0066] Embodiment 6 is any one of embodiments 1 to 5, wherein the element is completely dissolved in the molten beryllium.

[0061]

[0067] Embodiment 7 is any one of Embodiments 1 to 6, wherein the secondary phase is dispersed among the beryllium grains.

[0068] Embodiment 8 is any one of Embodiments 1 to 7, wherein the beryllium grains have an average grain size of 1 to 80 microns.

[0062]

[0069] Embodiment 9 is any one of Embodiments 1 to 7, wherein the beryllium grains have an average grain size of 5 to 40 microns.

[0070] Embodiment 10 is any one of Embodiments 1 to 7, wherein the beryllium grains have an average grain size of 5 to 25 microns.

[0063]

[0071] Embodiment 11 is any one of embodiments 1-10, wherein the element and / or nucleating agent is added to the beryllium powder by blending, atomization, mechanical alloying, or resonance mixing.

[0064]

[0072] Embodiment 12 is any one of Embodiments 1 to 11, in which 0.1 to 25 wt % of an element is added to the beryllium.

[0073] Embodiment 13 is any one of Embodiments 1 to 12, in which 0.1 to 10 wt % of an element is added to the beryllium.

[0065]

[0074] Embodiment 14 is any one of embodiments 1-13, wherein an electron beam or laser is used to apply energy to at least a portion of the layer.

[0075] Embodiment 15 is any one of embodiments 1 to 14, further comprising depositing the layer in a reducing atmosphere.

[0066]

[0076] Embodiment 16 is any one of embodiments 1-15, wherein the reducing atmosphere has a volume concentration of oxygen or other oxidizing agent of 10% or less by volume.

[0077] Embodiment 17 is any one of Embodiments 1 to 16, wherein the beryllium powder has a D50 average particle size of 10 to 50 microns.

[0067]

[0078] While the present invention has been described in detail, modifications within the spirit and scope of the present invention will be readily apparent to those skilled in the art. In view of the foregoing discussion, relevant knowledge in the art, and the references discussed above in connection with the Background Art and Detailed Description, the disclosures of which are incorporated herein by reference in their entirety. In addition, aspects of the present invention and portions of the various embodiments and features referred to below and / or in the appended claims may be combined or interchanged, either in whole or in part. In the foregoing description of various embodiments, embodiments referring to other embodiments may be appropriately combined with other embodiments, as will be recognized by those skilled in the art. Furthermore, those skilled in the art will recognize that the foregoing description is illustrative only and is not intended to be limiting.

Claims

1. 1. A method for producing a beryllium-based article, comprising: adding an element to the beryllium powder; depositing a layer comprising said beryllium powder on a surface; applying energy to at least a portion of the layer to form molten beryllium, wherein at least a portion of the elements are dissolved in the molten beryllium; solidifying the molten beryllium and forming a secondary phase from the dissolved elements; and repeating the depositing / applying / solidifying steps for successive layers to form the beryllium-based article. A method comprising:

2. The method of claim 1 , wherein the element comprises aluminum, silicon, or silver.

3. 3. The method of claim 1, wherein the element is completely dissolved in the molten beryllium.

4. The method of any one of claims 1 to 3, wherein the secondary phase is dispersed among the beryllium grains.

5. 5. The method of claim 4, wherein the beryllium grains have an average grain size of 1 to 80 microns, preferably an average grain size of 5 to 40 microns, or preferably an average grain size of 5 to 25 microns.

6. The method of any one of claims 1 to 5, wherein the element is added to the beryllium powder by blending, atomization, mechanical alloying or resonance mixing.

7. 7. The method according to claim 1, wherein 0.1 to 25% by weight of said element is added to beryllium.

8. 8. The method according to claim 1, wherein 0.1 to 10% by weight of said element is added to beryllium.

9. The method of any one of claims 1 to 8, wherein an electron beam or a laser is used to apply energy to at least a portion of the layer.

10. The method of any one of claims 1 to 9, further comprising depositing the layer in a reducing atmosphere.

11. 11. The method of claim 10, wherein the reducing atmosphere has a volume concentration of oxygen or other oxidizing agent of 10% or less by volume.

12. 12. The method of any one of claims 1 to 11, wherein the beryllium powder has a D50 average particle size of 10 to 50 microns.

13. The method of any one of claims 1 to 12, wherein a nucleating agent is added to the beryllium powder.

14. 14. The method of claim 13, wherein the nucleating agent comprises beryllium titanium, beryllium chromium, iron beryllium, beryllium zirconium, tantalum beryllide, beryllium molybdenum, niobium beryllium, beryllium tungsten, beryllium strontium, and / or beryllium hafnium.

15. 14. The method of claim 13, wherein the beryllium powder comprises 0 to 40 weight percent of the nucleating agent.

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