Coated forming tools with enhanced performance and extended service life

Abstract

A coated forming tool for processing plastic material or aluminum or aluminum alloy material, comprising a substrate (10) having a substrate surface (1), wherein the substrate surface (1) is coated with a coating (2) consisting of one or more layers, characterized in that the coating (2) comprises a Si-C-N base layer (3) whose elemental composition corresponds in atomic percentage to Si a C b N c X d , whose elements are selected from the elements hydrogen, oxygen, titanium, chromium and / or aluminum.

Description

[0001] The present invention relates to a coated forming tool which is particularly advantageous for processing plastics or processing aluminum or aluminum alloys. Such processing can include, for example, plastic injection molding and aluminum (or aluminum alloy) die casting. The coated forming tool of the present invention allows to obtain better performance and significantly longer service life than the coated forming tools known in the prior art.

[0002] The term "forming tool" in the context of the present invention must be understood as referring to any type of forming tool or forming tool part, including a mold or a mold part, which has a surface intended to contact the material to be processed, for example contacting plastic material in a plastic processing process or contacting aluminum (or aluminum alloy material) in an aluminum (or aluminum alloy) processing process.

[0003] Technical field and prior art

[0004] It is known to use coatings in forming tools to improve forming tool properties.

[0005] In an article entitled “Extrusion: Coating nozzle surfaces to avoid corrosion and wear” published in the magazine “Blasformen & Extrusionswerkzeuge”, edition 6 / 2008, it is reported that chemical nickel coatings applied to the surfaces of nozzles for extruding plastics offer significant advantages over other coatings with regard to corrosion resistance and wear resistance.

[0006] One of the most important advantages of these chemical nickel coatings should be that they can be deposited truly contoured to the surface of the tool or part to be coated. They should allow uniform coating of complex geometries, as well as bores and concave surfaces. The process temperature during the deposition of these coatings is at most 90°C. It is also reported that the service life obtained by using chemical nickel coatings is at least twice that obtained by using coatings formed by chrome plating. In addition, it is reported that the common troubles that occur during the removal of white polypropylene (PP) type plastic particles from blow molds can be avoided using this type of chemical nickel coating, especially by using a coating called "chemical-nickel-PTFE".

[0007] In the article entitled “New coating extends the service life of injection molds by a factor of 10” (author Stephane Itasse, published on the homepage of the specialist media “MaschinenMarkt”, 2015.09.22), it is reported that the coating Balinit A from Oerlikon Balzers is used to coat casting molds and that the service life can be extended by a factor of 10 using this coating.

[0008] However, in order to meet the extremely urgent need arising from the increasing requirements for productivity, economy, and reliability of the manufacturing process, new solutions must be provided.

[0009] Object of the Invention

[0010] The object of the present invention is to provide a solution for improving productivity, economy, and reliability of the manufacturing process in shaping processes, preferably in plastic processing and / or aluminum processing. The solution should preferably enable a significant extension of the service life of the shaping tools used in the corresponding processing.

[0011] Description of the Invention

[0012] The object of the present invention is achieved by providing a shaping tool, in particular a substrate, the surface of which is coated with a coating comprising a Si-C-N base layer containing silicon, carbon, and nitrogen as main components.

[0013] The elemental composition of the layer according to the invention can be expressed as follows:

[0014] Si a C b N c X d , where 50 < a + b + c ≤ 100, 0 ≤ d < 60, preferably 0 ≤ d < 50, and where X can be one or more elements selected from the following group of elements: H, O; Ti, Cr, Al. A possible preferred embodiment is 0 ≤ d < 55, a more preferred embodiment is 0 ≤ d < 50, an even more preferred embodiment is 0 ≤ d < 45, or a possibly more preferred embodiment is 0 ≤ d < 40.

[0015] Preferably, X contains hydrogen, or oxygen, or contains hydrogen and oxygen.

[0016] Preferably, X contains titanium, or chromium, or aluminum, or contains a combination of titanium, chromium, and / or aluminum.

[0017] According to a preferred embodiment, X corresponds to the elements H and O.

[0018] Furthermore, by depositing a Si-C-N base layer (a silicon carbonitride-based layer) having metal atoms such as Ti, Cr, and / or Al, additional benefits can be obtained in terms of coating properties. These metal elements can be incorporated into the coating, for example, by using typical CVD precursors such as TiCI4, AlCr3, and / or metal organic precursors.

[0019] Good results can be obtained in a preferred embodiment by using the Si-C-N base layer of the present invention having the elemental composition Si a C b N c Xd wherein, 60 < a + b + c ≤ 100 and 0 ≤ d < 60. A possible preferred embodiment is 0 ≤ d < 55, a more preferred embodiment is 0 ≤ d < 50, an even more preferred embodiment is 0 ≤ d < 45, or a more preferred embodiment is 0 ≤ d < 40.

[0020] To explain the present invention in more detail, certain preferred embodiments of the present invention will be described.

[0021] Figure 1-4 It should be helpful for understanding some preferred embodiments of the present invention.

[0022] The preferred embodiments in the following description of the present invention should not be construed as limitations of the present invention, but rather as illustrative examples for better understanding the present invention.

[0023] Figure 1 Schematically shows the structure of a coating system deposited on the substrate surface 1 of the substrate 10 of a forming tool according to the present invention, wherein the coating 2 is deposited as a single layer on the substrate surface 1, i.e., the coating 2 is formed by only one layer, and this layer is the Si - C - N base layer 3.

[0024] Figure 2 Schematically shows the structure of a coating system of another embodiment deposited on the substrate surface 1 of the substrate 10 of a forming tool according to the present invention, wherein the coating 2 is deposited as a multi - layer on the substrate surface 1, i.e., the coating 2 is formed by more than one layer, and the Si - C - N base layer is deposited as the top layer, and a hard thin film layer 5 is deposited between the substrate surface 1 and the Si - C - N base layer 3.

[0025] Figure 3 Schematically shows the structure of a coating system of another embodiment deposited on the substrate surface 1 of the substrate 10 of a forming tool according to the present invention, wherein the coating 2 is deposited as a multi - layer on the substrate surface 1, i.e., the coating 2 is formed by more than one layer, and the Si - C - N base layer 3 is deposited as the top layer, wherein the substrate 10 includes a nitride layer 4, wherein the nitride layer 4 preferably forms the substrate surface 1, and a hard thin film layer 5 is deposited between the nitride layer 4 and the Si - C - N base layer 3.

[0026] Figure 4 Schematically shows the structure of a coating system of another embodiment deposited on the substrate surface 1 of the substrate 10 of a forming tool according to the present invention, wherein the coating 2 is deposited as a multi - layer on the adhesion layer 6, wherein the substrate 10 includes a nitride layer 4, wherein the nitride layer 4 preferably forms the substrate surface 1, wherein the adhesion layer 6 is deposited on the nitride layer 4 which preferably includes the substrate surface 1 as described above, wherein the Si - C - N base layer 3 is deposited as the top layer, and a hard thin film layer 5 is deposited between the adhesion layer 6 and the Si - C - N base layer 3.

[0027] The inventors have found that a very good improvement in the performance and service life of forming tools, in particular in plastics processing and aluminium processing, can be achieved if a Si-CN based layer 3 is deposited as the outermost layer of the coating 2.

[0028] The Si-CN based layer 3 of the present invention is preferably deposited to show:

[0029] - an amorphous layer structure, and / or

[0030] - free of droplets (droplets are often formed in coatings deposited by a vapor phase deposition (PVD) process, in particular by using an unfiltered arc vapor deposition process), and / or

[0031] -High corrosion resistance.

[0032] Preferably, the Si—CN based layer 3 of the present invention exhibits all the above properties simultaneously.

[0033] By depositing the Si-CN based layer 3 of the present invention as the top layer of the coating 2, the following additional benefits can also be obtained:

[0034] - the forming tool material is chemically non-reactive (inert) during contact with the plastic material being processed, and / or

[0035] - Reduce the tendency of the forming tool material to adhere to the molten plastic during processing.

[0036] According to a preferred embodiment of the present invention, the coating 2 is composed of only one Si-CN based layer 3. In this case, the Si-CN based layer 3 can be directly deposited on the substrate surface 1, such as Figure 1 It may also be beneficial that, additionally, an adhesion layer 6 may be deposited between the substrate surface 1 and the Si-CN based layer 3 constituting the coating 2 in order to improve the adhesion of the coating 2 to the substrate surface 1 .

[0037] By providing the coating according to the invention on a forming tool according to a first embodiment (see for example Figure 1 ), and obtain the following advantages:

[0038] - inertness (chemical non-reaction) during contact with plastic materials, and / or

[0039] - Improved corrosion resistance compared to low-alloyed bulk materials (e.g. with ≤5 wt. % chromium) used to make forming tools (e.g. tempered tool steels such as heat-treatable cold tool steels 1.2311 and 1.2312; hardened tool steels such as hot tool steels 1.2343 and 1.2344; nitrided steels such as heat-treatable steels 1.7735, 1.8519 and 1.8550).

[0040] Preferably, the first embodiment obtains all the above advantages simultaneously.

[0041] According to another preferred second embodiment of the present invention, the deposited coating 2 has a multilayer structure, which includes at least two layers, one of which is a Si-CN base layer 3 deposited as the outermost layer, preferably the top layer, such as Figure 2 In this case, the first layer 5 of the multilayer structure can be as shown. Figure 2 As shown, it is deposited directly on the substrate surface 1. Figure 2 In the case shown, the first layer 5 is deposited between the substrate surface 1 and the Si-CN based layer 3. In this embodiment, it may be advantageous if the adhesion layer 6 (on Figure 2 The bonding layer 6 (not shown) is deposited between the substrate surface 1 and the first layer 5 of the multilayer structure forming the coating 2 in this embodiment, wherein the bonding layer 6 is used to improve the adhesion of the coating 2 to the substrate surface 1.

[0042] By providing the coating according to the invention on a forming tool according to a second embodiment (see for example Figure 2 ), and obtain the following advantages:

[0043] - inertness (chemical non-reaction) during contact with plastic materials, and / or

[0044] - improved corrosion resistance compared to low alloyed bulk materials (e.g. with ≤ 5 wt. % chromium) used to make forming tools (see above for examples of typical forming tool materials), and / or

[0045] - an increase in the overall coating hardness due to the inclusion of a hard coating layer (e.g. a metal nitride layer) in the multilayer structure forming the coating 2, for example due to the inclusion of a PVD-deposited nitride layer as the first layer 5 of the coating 2, and / or

[0046] - Improved contact pressure per unit area in relation to hard particles in the plastic.

[0047] Preferably, the second embodiment obtains all the above advantages simultaneously.

[0048] For a better understanding of the term "improved contact pressure", the following examples will be explained:

[0049] With the aid of the first layer 5, support is provided for the top layer 3 (Si-CN based layer 3), for example if the thickness of the first layer 5 is greater than 5 μm, preferably greater than 10 μm and the first layer is harder than the top layer 3. In the plastic, for example, these are hard particles. When forming the plastic in a coating forming tool, there is a risk that hard particles of the plastic may become lodged in the top layer 3, especially if there is no support below the top layer 3 and especially if the bulk material does not have a surface hardness of more than, for example, 550 HV. With the first layer 5 and preferably an additional nitrided layer 4 (see Figure 3and / or Figure 4 And preferably see the third embodiment of the invention described below), the contact pressure per unit area can be improved with respect to hard particles, for example in plastic molding.

[0050] According to another preferred third embodiment of the present invention, the substrate surface 1 is treated in such a way that a nitride layer 4 is formed on the surface of the substrate 10 so that the nitride layer 4 includes the substrate surface 1. In this way, the coating 2 is deposited on the nitride layer 4 constituting the substrate surface 1 (e.g. Figure 3 It may be advantageous if the coating 2 is deposited on an adhesion layer 6 which is deposited on a nitride layer 4 comprising the substrate surface 1 (e.g. Figure 4 As shown in Figure 4 The adhesion layer structure shown appears to be useful and promising.

[0051] By providing the coating according to the invention on the forming tool according to this third embodiment (see for example Figure 3 or Figure 4 ), and obtain the following advantages:

[0052] - Further improvement in the contact pressure per unit area of ​​the hard particles in the plastic (with Figure 2 higher contact pressure compared to the embodiment shown), and / or

[0053] - improved mechanical stability of the substrate coating system by providing better support of the coating on the forming tool substrate material, which is typically steel, having a significantly lower hardness (e.g. steel hardness ≤ 550 HV) than the coating hardness, and / or

[0054] - improved high temperature mechanical strength (up to 500° C. without loss of advantageous mechanical properties in the nitrided layer 4, wherein the high hardness is also retained at a processing temperature of 500° C.), and / or

[0055] - Improved cracking behavior / extension (crack propagation into the bulk is improved. Cracks mostly stop in the nitrided layer 4, preferably at the end of the nitriding depth, due to induced internal stresses associated with the nitrogen inventory in the surface area. The top layer 3 and the first layer 5 preferably guide cracks parallel to the surface and protect the substrate).

[0056] Preferably, the third embodiment obtains all the above advantages simultaneously.

[0057] The inventors have found that, unexpectedly, the forming tool coated or treated and coated according to any of the above preferred third embodiments (see also Figure 3 and / or Figure 4) can obtain a significantly longer service life by depositing a coating 2, which includes at least one corrosion-resistant layer (for example, a hard film layer 5 showing good corrosion resistance), which is deposited between the Si-CN-based outermost layer 3 and the substrate surface 1 (depending on the situation, the corrosion-resistant layer 5 can be deposited, for example, between the Si-CN-based outermost layer 3 and the adhesion layer 6 or between the Si-CN-based layer 3 and the nitride layer 4 comprising the substrate surface 1).

[0058] The hard film layer 5 is preferably a metal nitride layer, a metal oxide layer, a metal oxynitride layer, a metal carbonitride layer, or a metal carbonitride layer. The hard film layer 5 preferably has a carbon atom percentage corresponding to the chemical formula Me(C v N y O z ) q A chemical composition wherein Me is one or more elements selected from the group consisting of chromium, aluminum, titanium, vanadium and molybdenum, wherein the atomic fractions v, y and z of carbon, nitrogen and oxygen respectively have values ​​in the range of 0≤v≤1, 0≤y≤1, 0≤z≤1, wherein v+y+z=1, and wherein the molar concentration q of the non-metallic elements C, N and O relative to 1 mole of the metal element Me is in the range of 0.76≤q≤1.2.

[0059] The corrosion-resistant layer is preferably a chromium nitride layer or a chromium nitride-based layer. In the context of the present specification, the chromium nitride-based layer is a layer containing chromium nitride, wherein, taking into account all elements present in the chromium nitride-based layer, the sum of the chromium content and the nitrogen content in the chromium nitride-based layer constitutes more than 50% by atomic percentage. The chromium nitride layer or chromium nitride-based layer used as a corrosion-resistant layer in the context of the present invention can be implemented as a chromium nitride layer showing a single-layer structure or a multi-layer structure. According to a preferred embodiment, the corrosion-resistant layer is implemented as a chromium nitride layer showing a multi-layer structure, wherein the multi-layer structure comprises at least two chromium nitride layers, preferably two different chromium nitride layers, for example a first chromium nitride layer and a second chromium nitride layer, wherein one of the two chromium nitride layers contains more nitrogen than the other, and wherein different types of layers are deposited alternately and overlappingly.

[0060] According to a preferred variant of the embodiment comprising a corrosion resistant layer, the Si—CN based layer 3 is deposited directly on the corrosion resistant layer.

[0061] According to a preferred variant of the embodiment comprising a corrosion resistant layer, the corrosion resistant layer is deposited directly on the substrate surface 1 or directly on the nitride layer 4 comprising the substrate surface 1 .

[0062] According to another preferred embodiment of the present invention, a thermochemical-based diffusion layer with nitrogen and carbon as diffusion elements may be used as the corrosion-resistant layer.

[0063] In a preferred embodiment, a thermochemical diffusion layer is used as the corrosion resistant layer and stainless steel or martensitic steel is used as the substrate material:

[0064] For the treatment of austenitic steels and non-corrosive martensitic steels, a preferred variant for producing a thermochemically based diffusion layer is low-temperature nitriding or low-temperature carbonitriding or carburizing (low temperature in this context is, for example, a temperature in the range of 360° C. to 460° C.). The diffusing elements N and C generate nitrogen at low temperatures to expand austenite and martensite, which improves pitting corrosion.

[0065] By including a Si-CN based layer above the above described thermochemical based diffusion layer, the following improvements are obtained:

[0066] o Additional improvement in corrosion resistance, and / or

[0067] o improved contact pressure per unit area in connection with hard particles in the plastic material (provided by the high hardness > 550 HV of the nitrided zone), and / or

[0068] o Improved mechanical stability compared to a steel substrate having a preferably much lower hardness than the coating, by providing better support for the coating (such as the Si-CN based layer 3) on the thermochemically based diffusion layer.

[0069] In another preferred embodiment, a thermochemical diffusion layer is used as the corrosion resistant layer and heat-treatable steel, carbon steel, case-hardened steel, nitrided steel or thermal steel is used as the substrate material:

[0070] To process such low alloy steels, the preferred variant for producing a diffusion layer based on thermochemistry is carbonitriding with a Fe(N,C) nitride layer, preferably an Epsilon nitride layer, as the corrosion protection layer, or carbonitriding plus reoxidation with a composite Epsilon nitride as the corrosion protection layer. The Si-CN layer is preferably deposited directly on the Epsilon nitride composite material. Only optionally, a magnetite layer is used as the corrosion protection layer.

[0071] The following improvements are obtained by including a Si-CN based layer 3 above the above mentioned thermochemical based diffusion layer:

[0072] o Additional improvement in corrosion resistance, and / or

[0073] o improved contact pressure per unit area in connection with hard particles in the plastic material (caused by the high hardness of the nitrided zone > 550 HV), and / or

[0074] o Improved mechanical stability compared to a steel substrate having preferably a significantly lower hardness than the coating by providing better support for the coating on a thermochemically based diffusion layer (e.g. Si-CN based layer), and / or

[0075] o Improved high temperature mechanical strength, and / or

[0076] o Improved cracking behavior / propagation (improved crack propagation into the bulk material due to the advantage of the nitride layer stopping the cracking process by induced internal stresses generated by the nitrogen present in the surface zone), and / or

[0077] o Reduces the tendency of forming tool material to adhere to molten plastic and non-ferrous metals such as aluminum and copper.

[0078] Preferably, the above embodiments achieve all the above improvements simultaneously.

[0079] The inventors have discovered that a Si-CN based layer 3 deposited using plasma enhanced chemical vapor deposition (PE-CVD) techniques (these techniques are also known as plasma assisted chemical vapor deposition (PA-CVD) techniques) is particularly beneficial for improving tool performance and lifetime.

[0080] For the PE-CVD deposition of the Si-CN layer 3 of the present invention, a gas containing Si and C can be used. For example, gaseous hexamethyldisiloxane (HMDSO) can be used as a precursor, and nitrogen can be used as a reaction gas to form the Si-CN base layer. The Si-CN layer deposited in this way shows a particularly low surface roughness. For example, in an example where the substrate surface 1 shows an arithmetic average roughness Ra=0.01μm before coating, the arithmetic average roughness obtained after coating is Ra=0.04μm, and the coating of the present invention shows as follows Figure 1 The structure shown in FIG. 1 shows a total layer thickness of 8 μm for the Si-CN base layer 3 produced by the PE-CVD method described above. In another example, the substrate surface 1 also shows an arithmetic mean roughness Ra=0.01 μm before coating, and the arithmetic mean roughness obtained after coating is Ra=0.02 to 0.03 μm. In this case, the coating of the present invention shows a roughness of 0.01 μm. Figure 1 In the structure shown, the Si-CN-based layer 3 produced by the above-described PE-CVD method has a total layer thickness of 2 to 3 μm.

[0081] However, the deposition of the Si-CN layer of the present invention is not limited to the above method. The Si-CN layer can also be deposited by any PVD method or reactive PVD method, for example:

[0082] - by sputtering a target comprising silicon, carbon and nitrogen in an argon-containing atmosphere or in an argon-containing atmosphere, or

[0083] - by sputtering or arc vaporization of a target containing silicon and carbon in a nitrogen-containing atmosphere.

[0084] However, all of the above methods should be understood as examples and should not be understood as limitations on the methods that can be used to deposit the Si-CN layer of the present invention.

[0085] In order to obtain better performance of the forming tool, the coated or treated and coated forming tool according to the present invention can preferably be post-treated to obtain the desired surface quality. Some suitable post-treatments in this regard are, for example:

[0086] - Grind with 1200 grit or finer, and / or

[0087] - Glass bead blasting, and / or

[0088] - Polish with diamond paste.

[0089] The selection of the structure and elemental composition of the coating system used to improve the performance and extend the service life of the forming tool of the present invention can be carried out according to the following conditions:

[0090] - the type of plastics processing and / or the type of plastics material to be processed,

[0091] or

[0092] - Type of aluminum processing and / or type of aluminum alloy to be processed.

[0093] Example 1 of the present invention:

[0094] A calibration gauge for wet calibration of window profile extrusion was used as the substrate.

[0095] The substrate materials used are: hot tool steels 1.2311 and 1.2316.

[0096] The substrate is introduced into the coating chamber of the vacuum coating equipment for the coating process according to the present invention. The coating is deposited on the substrate, the coating comprising two layers, namely a first layer 5 of chromium nitride and a second layer which is a Si-CN based layer 3. The first layer 5 is deposited directly on the surface of the calibration gauge intended to contact the material to be treated. The contact material to be in contact with the Si-CN based layer 3 is polyvinyl chloride (PVC).

[0097] The chromium nitride layer (hereinafter also referred to as CrN layer) is deposited by using a physical vapor deposition (PVD) technique, preferably of the reactive cathode arc vaporization type. The hard material coating (chromium nitride) is preferably carried out in a PVD system (arc PVD or magnetron PVD system). To deposit the first layer 5, a chromium target is vaporized in a nitrogen-containing atmosphere, and a bias voltage, preferably a bias voltage of at least 50 volts, preferably a bias voltage of up to 300 volts, preferably a bias voltage between 50 volts and 300 volts, is applied to the calibration gauge.

[0098] The following process steps are carried out before and during the deposition of the first layer 5 (in this example: chromium nitride deposited by reactive cathodic arc PVD):

[0099] 1. Evacuate to high vacuum

[0100] 2. Thermal radiation heating up to 400°C

[0101] 3. Sputtering cleaning by argon ion / metal ion bombardment

[0102] 4. A chromium target is used as the cathode in a reactive cathodic arc gasification process, in which a nitrogen-argon mixed gas flow is used as the process gas / reactant gas and a bias voltage is applied to the substrate.

[0103] The second layer 3 is deposited as the outermost layer using PE-CVD. The deposition of the second layer 3 is preferably carried out in a plasma nitridation system. For the deposition of the second layer, gaseous HMDSO is used as a precursor, nitrogen is fed into the coating chamber, and the deposition temperature (the temperature of the coated substrate surface during the deposition process) is maintained between 360°C, preferably 380°C and 450°C, preferably 480°C.

[0104] The following process steps are performed after the deposition of the first layer 5 and during the deposition of the second layer 3 (in this example: a Si-CN based layer deposited by PE-CVD):

[0105] 5. Turn off the chromium target, stop the gas flow into the coating chamber and evacuate the coating chamber.

[0106] 6. Send a mixture flow of hydrogen, nitrogen and argon (H2, N2 and argon mixture flow) into the coating chamber.

[0107] 7. Switch on the glow discharge directly on the substrate (sample or forming tool) by increasing the bias voltage on the substrate to a value in the range of 500V to 600V.

[0108] 8. Turn on the vapor evaporator for HMDSO and 5% HMDSO dosage to the H2, N2 and Argon mixture flow.

[0109] The second layer thus deposited produces Si a C b N c X d The Si-CN based layer 3 of the type, wherein X is the elements hydrogen (H) and oxygen (O), and the coefficient d corresponds to the sum of the H content and the O content in atomic percentage in the Si-CN based layer 3. Therefore, the elemental composition of such a Si-CN based layer 3 can be expressed as follows:

[0110] Si a C b N cH d1 O d2 , where d1+d2=d

[0111] For the test in this example, the composition of the Si-CN base layer obtained is as follows: Si 28 C 29 N 12 H 19 O 12

[0112] In this example, the CrN layer is deposited to have a multilayer structure of Cr / CrN / Cr / CrN... and has a multilayer structure layer thickness of 6 to 8 μm or has a multilayer structure layer thickness of 8 to 10 μm (the preferred thickness range of this CrN layer or any other type of first layer is: 1 to 10 μm).

[0113] Preferably, a layer thickness of more than about 8 μm with good adhesion strength can be deposited on the substrate 10 of the forming tool, preferably at about 480° C. (see Figure 1 ). The hardness of these layers is preferably in the order of 5000 HV0.1.

[0114] The corrosion resistance of the layer with a thickness of about 2 μm is preferably 144 to 188 h in the salt spray test. Figure 1 The corrosion resistance of thicker layers is believed to be at least as good as the 2 μm thick layer, which is preferably more corrosion resistant, but is being tested at this time.

[0115] According to a preferred embodiment of the CrN layer with a multilayer structure, the stacking of these layers preferably always starts with Cr, followed by CrN, followed by, for example, five of these stacks. The ratio of Cr to CrN is preferably 1 / 5.

[0116] In this example, the Si—CN based layer 3 is deposited to have a layer thickness of 1-2 μm, wherein a preferred thickness range for such a Si—CN based layer is 1 to 10 μm.

[0117] The calibration gauge so coated showed no visible signs of corrosion after 48 hours of use.

[0118] The specification and claims of the priority application US 62 / 853,969 filed on May 29, 2019, on which this application is based should preferably form an integral part thereof.

[0119] As described in this specification, a main objective is to deposit multiple layers on tools used in the plastic and aluminum processing industries. Specifically, the "Si-C-N base layer directly on the nitrided layer" has hitherto been studied for qualification within an application temperature range of 360°C to 480°C. PE-CVD or PA-CVD can be the preferred techniques for depositing the Si-C-N layer. It may be preferred to treat the layer with glass beads or diamond paste. As described in one of the embodiments above, it is preferred that the deposition process will initially be carried out in two different devices, where, for example, a hard material coating (chromium nitride) is deposited in a PVD system (arc PVD or magnetron PVD system), and then the deposition of Si-C-N is carried out in a plasma nitriding system. As Figure 4 The adhesion layer structures shown and described above may be useful and promising.

[0120] The above and those Figures 1 to 4 described in the coating systems can also open up interesting application areas for precision components due to their properties - especially due to corrosion resistance, high hardness, and non-conductivity. For example, for improving the properties of machined metal parts, stainless steel parts, and castings, and for improving the properties of metal parts in electronic applications, especially due to the electrical insulation characteristics of the Si-C-N base layer of the present invention.

[0121] Regardless of the claims, the following is also claimed:

[0122] A coated forming tool for processing plastic materials or aluminum or aluminum alloy materials, comprising a substrate 10 having a substrate surface 1, the substrate surface 1 being coated with a coating 2 composed of one or more layers, characterized in that the coating 2 comprises a Si-C-N base layer 3, the elemental composition of which corresponds by atomic percentage to Si a C b N c X d , where 50 < a + b + c ≤ 100, 0 ≤ d < 50, where X is one or more elements selected from the group of elements consisting of the non-metallic elements hydrogen and oxygen and the metallic elements titanium, chromium, and aluminum.

[0123] The coated forming tool according to the previous paragraph, characterized in that the coating is formed by more than one layer, and the Si-C-N base layer 3 is deposited as the outermost layer.

[0124] The coated forming tool according to one of the foregoing paragraphs, characterized in that the substrate surface 1 comprises a nitrided layer 4, and the coating 2 is deposited on the nitrided layer.

[0125] The coated forming tool according to one of the foregoing paragraphs, characterized in that the coating 2 comprises a hard thin film layer 5, which is deposited between the substrate surface 1 and the silicon carbonitride layer 3.

[0126] The coated forming tool according to the previous paragraph is characterized in that the hard film layer 5 is a metal nitride layer or a metal oxide layer or a metal oxynitride layer or a metal carbon oxynitride layer or a metal carbon nitride layer, wherein the chemical composition of the hard film layer 5 corresponds in atomic percentage to the chemical formula Me(C v N y O z ) q , wherein Me is one or more elements selected from the group consisting of chromium, aluminum, titanium, vanadium and molybdenum, and the atomic fractions v, y and z of carbon, nitrogen and oxygen respectively have values ​​in the following ranges, 0≤v≤1, 0≤y≤1, 0≤z≤1, wherein v+y+z=1, and the molar concentration q of the non-metallic elements C, N and O relative to 1 mole of the metal element is in the following range: 0.76≤q≤1.2.

[0127] The coating forming tool according to one of the preceding paragraphs is characterized in that an adhesion layer 6 is deposited between the substrate surface 1 and the coating 2 .

[0128] A coated forming tool according to one of the preceding paragraphs, characterized in that the Si—CN based layer 3 contains hydrogen and oxygen in addition to silicon, carbon and nitrogen.

[0129] A method for producing a coated forming tool according to one of the preceding paragraphs, characterized in that the silicon carbonitride layer 3 is deposited by means of PE-CVD technology, wherein a silicon-containing gas is used as precursor.

[0130] The method according to the preceding paragraph, characterized in that the silicon-containing gas is hexamethyldisiloxane (HMDSO).

[0131] The method according to one of the two preceding paragraphs is characterized in that, before depositing the silicon carbonitride layer 3, the substrate 10 to be coated is subjected to a plasma nitridation process to form a nitride layer 4 comprising the substrate surface 1 on which the coating 2 is deposited.

[0132] Use of a coated molding tool according to one of the preceding paragraphs in a plastics processing process.

[0133] The use according to the preceding paragraph is characterized in that the plastic processing is plastic injection molding.

[0134] Use of a coated forming tool according to one of the preceding paragraphs in processing aluminium or aluminium alloys.

[0135] The use according to the preceding paragraph is characterized in that the plastic processing is aluminum die casting or aluminum alloy die casting.

[0136] Regardless of the claims, independently of the claims and / or in combination with any claim and / or in combination with one or more of the foregoing paragraphs, there is also claimed a coated forming tool for processing plastic materials or aluminum or aluminum alloy materials, which comprises a substrate 10 having a substrate surface 1, wherein the substrate surface 1 is coated with a coating 2 consisting of one or more layers, characterized in that the coating 2 comprises a Si-C-N base layer 3, the elemental composition of which corresponds, in atomic percentages, to Si a C b N c X d , where 50 < a + b + c ≤ 100, 0 ≤ d < 60, preferably 0 ≤ d < 50, where X is one or more elements selected from the elements hydrogen, oxygen, titanium, chromium and aluminum.

[0137] Regardless of the claims, independently of the claims and / or in combination with any claim and / or in combination with one or more of the foregoing paragraphs, there is also claimed a coated forming tool, wherein X comprises hydrogen, or oxygen, or comprises hydrogen and oxygen.

[0138] Regardless of the claims, independently of the claims and / or in combination with any claim and / or in combination with one or more of the foregoing paragraphs, there is also claimed a coated forming tool, wherein X comprises titanium, or chromium, or aluminum, or comprises a combination of titanium, chromium and / or aluminum.

[0139] Regardless of the claims, independently of the claims and / or in combination with any claim and / or in combination with one or more of the foregoing paragraphs, there is also claimed a coated forming tool, wherein X is one or more elements selected from the group of elements consisting of the non-metallic elements hydrogen and oxygen and the metallic elements titanium, chromium and aluminum.

Claims

1. A coated forming tool for processing plastic material or aluminum or aluminum alloy material, the coated forming tool being used for plastic injection molding or aluminum die casting or aluminum alloy die casting, comprising a substrate (10) having a substrate surface (1), wherein: The surface (1) of the substrate is coated with a coating (2) composed of one or more layers, characterized in that the coating (2) comprises a Si-C-N base layer (3), the elemental composition of which corresponds, in atomic percentages, to Si a C b N c X d , where 50 < a + b + c < 100, 0 < d < 60, where X comprises hydrogen and oxygen.

2. The coating forming tool according to claim 1, characterized in that: 0<d<50。 3. The coating forming tool according to claim 1, characterized in that: X also contains titanium, or chromium, or aluminum.

4. The coated forming tool according to any one of claims 1 to 3, characterized in that: The coating (2) is formed of more than one layer, and the Si-CN based layer (3) is deposited as the outermost layer.

5. The coating forming tool according to claim 1, characterized in that: The substrate surface (1) comprises a nitride layer (4) and the coating (2) is deposited on the nitride layer.

6. The coating forming tool according to claim 1, characterized in that: The coating (2) comprises a hard film layer (5) deposited between the substrate surface (1) and the Si-CN based layer (3).

7. The coating forming tool according to claim 6, characterized in that: The hard film layer (5) is a metal nitride layer or a metal oxide layer or a metal oxynitride layer or a metal carbon oxynitride layer or a metal carbon nitride layer, wherein the chemical composition of the hard film layer (5) corresponds to the chemical formula Me(C v N y O z ) q , wherein Me is one or more elements selected from the group consisting of chromium, aluminum, titanium, vanadium and molybdenum, and wherein the atomic fractions v, y and z of carbon, nitrogen and oxygen respectively have values ​​in the following ranges, 0≤v≤1, 0≤y≤1, 0≤z≤1, wherein v+y+z=1, and wherein the molar concentration q of the non-metallic elements C, N and O relative to 1 mole of the metal element Me is in the following range, 0.76≤q≤1.

2.

8. The coating forming tool according to claim 1, characterized in that: An adhesion layer (6) is deposited between the substrate surface (1) and the coating (2).

9. A method for manufacturing a coated forming tool according to any one of claims 1 to 8, characterized in that: The Si-CN based layer (3) is deposited using PE-CVD technology, wherein a silicon-containing gas is used as a precursor.

10. The method according to claim 9, characterized in that: The silicon-containing gas is hexamethyldisiloxane (HMDSO).

11. The method according to claim 9 or 10, characterized in that: Prior to depositing the silicon carbonitride layer (3), the substrate (10) to be coated is subjected to a plasma nitridation treatment to form a nitride layer (4) comprising the substrate surface (1) on which the coating (2) is deposited.

12. Use of a coated forming tool according to any one of claims 1 to 8 in a plastics processing process.

13. The use according to claim 12, characterized in that: The plastic processing is plastic injection molding.

14. Use of a coated forming tool according to any one of claims 1 to 8 in processing aluminium or aluminium alloys.

15. The use according to claim 14, characterized in that: The aluminum or aluminum alloy processing is aluminum die casting or aluminum alloy die casting.

Images