EP4357471A1

EP4357471A1 - Nickel-chrome alloys

Info

Publication number: EP4357471A1
Application number: EP22202777.3A
Authority: EP
Inventors: Oliver Lanz
Original assignee: Hoganas Germany GmbH
Current assignee: Hoganas Germany GmbH
Priority date: 2022-10-20
Filing date: 2022-10-20
Publication date: 2024-04-24
Also published as: WO2024084057A2; WO2024084057A3

Abstract

Herein is disclosed nickel-chrome alloys suitable for use as matrix alloys for holding particles of metal carbides for high abrasive wear resistance in high carbide volume fractions with high corrosion resistance. Further, direct synthesis of nickel-chrome alloys of the disclosure containing precipitates of metal carbides are detailed.

Description

TECHNICAL FIELD

The present disclosure concerns nickel-chrome alloys suitable for use as matrix alloys for holding particles of metal carbides for high abrasive wear resistance in high carbide volume fractions with high corrosion resistance. Further, direct synthesis of nickel-chrome alloys of the disclosure containing precipitates of metal carbides are detailed.

BACKGROUND

German patent application DE19901170A1 describes a Fe-based alloy, which is high in metal carbide formers like V, Cr, Mo, W, for providing a high carbide volume fraction that can provide an outstanding high abrasive wear resistance. Disadvantages are the missing corrosion resistance due to Cr depletion of the Fe-based matrix and the lack of impact tolerance of the Fe-based alloy.
These challenges are present in general with Fe-based alloys and blends which reduces potential applications, application technologies and lower the demand of these materials.
Known alloys, which are all Fe-based, contain the risk of undesired phase transformation such as martensite or delta ferrite, or the risk of incomplete martensitic phase transformation which retains residual austenite while applying them with casting/thermal spraying/surface welding/AM, leading for example to undesired level of hardness or undesirable brittleness.
In K. Bobzin et.al., New Possibilities for Fe-based HVAF-sprayed coatings, 11. Kolloquium HVOF Spraying 2018, Conference Proceedings, 19-30 general needs for corrosion and wear resistant alloys based on Fe (e.g., FeCrMnBC) are discussed. The desired hard phases such as borides provide wear resistance while Cr is kept high to provide a corrosion resistance of the Fe-based alloy. One way to increase wear resistance further is to blend in TiC hard phase reinforcement into a high alloyed metallic Fe base matrix. This metal matrix composite oxidizes during thermal spraying, precipitates Cr_xC_y and increases the oxide-content. These effects reduce the corrosion resistance of the coating and can bring an imbalance of the desired hard phases (e.g., Cr_xC_y instead of TiC or BC with Cr depletion of the Fe-based matrix). An additional result is a mismatch of mechanical properties like hardness and ductility. A similar powder blend made of FeCrB, and a WC-Co was described as well, wherein the FeCrB matrix provided higher corrosion and wear resistance while WC-Co is acting as a hard phase component. The result is a thermal spray coating which is characterized by the particle properties of the individual constituents since the powder is still a blend. Some particles act as hard phase components, other particles act as matrix with some corrosion resistance, making the coating properties locally inconsistent and the resulting coating sensitive to variations caused by inhomogeneities of the powder blend or due to inconsistent deposition efficacy. Additionally, the challenges due to Cr depletion from oxidation still exists.
The hardness of these Fe-based alloys and blends as described above is in the range of 615/670 HV0.3 for the FeCrMnBC/TiC coating and 67-68 HRC for the alloy in Patent DE19901170A1 . AMPERWELD CCA4 respectively AMPERIT 380.088 (c.f. DE19901170A1 ) has a hardness of approx. 60 HRC after surface welding and 800-850 HV0.3 as HVOF sprayed.

DETAILED DESCRIPTION

In a first aspect and embodiment of the present disclosure, there is herein detailed a Ni-based matrix alloy consisting by total weight of the alloy of: chromium (Cr) 12 wt% - 23 wt%, vanadium (V) 0.2 wt% - 3.1 wt%, tungsten (W) 1.0 wt% - 6.0 wt%, molybdenum (Mo) 0.6 wt% - 3.5 wt%, and optionally silicon (Si) 0 wt% - 2 wt%, manganese (Mn) 0 wt% - 2 wt%, aluminum (Al) 0 wt% - 1 wt%, the balance being nickel (Ni) and unavoidable impurities.
The present inventors have surprisingly found, that when alloys according to the present invention are formed by joint or stepwise melting of the constituent metals, a nickel-chrome alloy is formed which has improved corrosion resistive properties compared to reference products in the current market, while being very suitable for holding as micro-inclusions inside the formed alloy matrix, for example metal carbide particles in high volume fractions.
A further benefit of the present alloys is that some contamination with silicon, manganese, and aluminum is possible without loss of the beneficial properties of the present alloys, hence rendering sourcing of the constituent materials cheaper, since nickel-chrome scrap metal can be used to an extent as raw material or as an additive to the raw materials. As discussed herein below, each of silicon, manganese, or aluminum is typically introduced into the present alloys by direct synthesis of a present alloys and on or more metal carbides taking place in e.g., in powder form from thermal spraying (e.g., HVOF or HVAF), surface welding (e.g., PTA welding or Laser Cladding) or Additive Manufacturing (e.g., Powder Bed Fusion or Direct Energy Deposition).
Iron, which in the context of the present invention is considered an undesired impurity due to its high corrosive potential, may nonetheless be present in amounts up to 0.2 wt% without negative impact on the present alloys beyond miscoloring if exposed to corrosive conditions. Preferably, iron is not present in amounts exceeding 0.1 wt%, however scrap nickel-chrome alloys preferably used as source for the present alloys often contain this much of residual iron, and the present inventors consider it highly beneficial for cost that higher purity nickel-chrome source metals are not required.
In relation to the present alloys, chromium (Cr) may be present in amounts from 12 wt% to 23 wt% based on the total weight of the present alloys. Preferably, chromium is present from 13 wt% to 22 wt%, from 14 wt% to 21 wt%, from 15 wt% to 20 wt%, from 16 wt% to 19 wt%, or from 17 wt% to 18 wt% in the present alloys.
In relation to the present alloys, vanadium (V) may be present in amounts from 0.2 wt% to 3.1 wt% based on the total weight of the present alloys. Preferably, vanadium is present from 0.3 wt% to 3.0 wt%, from 0.4 wt% to 2.9 wt%, from 0.5 wt% to 2.8 wt%, from 0.6 wt% to 2.7 wt%, from 0.6 wt% to 2.7 wt%, from 0.7 wt% to 2.6 wt%, from 0.8 wt% to 2.5 wt%, from 0.9 wt% to 2.4 wt%, from 1.0 wt% to 2.3 wt%, from 1.2 wt% to 2.1 wt%, from 1.4 wt% to 1.9 wt%, or from 1.6 wt% to 1.7 wt% in the present alloys.
In relation to the present alloys, tungsten (W) may be present in amounts from 1.0 wt% to 6.0 wt% based on the total weight of the present alloys. Preferably, tungsten is present from 1.5 wt% to 5.5 wt%, from 2.0 wt% to 5.0 wt%, from 2.5 wt% to 4.5 wt%, from 3.0 wt% to 4.0 wt%, or from 3.3 wt% to 3.7 wt% in the present alloys.
In relation to the present alloys, molybdenum (Mo) may be present in amounts from 0.6 wt% to 3.5 wt% based on the total weight of the present alloys. Preferably, molybdenum is present from 0.7 wt% to 3.4 wt%, from 0.8 wt% to 3.3 wt%, from 0.9 wt% to 3.2 wt%, from 1.0 wt% to 3.0 wt%, from 1.3 wt% to 2.7 wt%, from 1.6 wt% to 2.4 wt%, or from 1.8 wt% to 2.2 wt% in the present alloys.
It is an advantage of the presently disclosed Ni-based matrix alloys that these can be formed in-situ by from a powder form by e.g., thermal spraying (e.g., HVOF or HVAF), surface welding (e.g., PTA welding or Laser Cladding) or Additive Manufacturing (e.g., Powder Bed Fusion or Direct Energy Deposition) . This allows simple manufacturing of the required powders using standard powder technology as known in the art, e.g., by mixing the constituent metals as powders or by pre-alloying the Ni-based matrix alloy and subsequently forming a suitable powder therefrom.
Accordingly, in an aspect and embodiment thereof, there is herein detailed a Ni-based powder composition at least comprising: chromium (Cr) from 12 wt% to 23 wt%, vanadium (V) from 0.2 wt% to 3.1 wt%, tungsten (W) from 1.0 wt% to 6.0 wt%, molybdenum (Mo) from 0.6 wt% to 3.5 wt%, and optionally silicon (Si) from 0 wt% to 2 wt%, manganese (Mn) from 0 wt% to 2 wt%, aluminum (Al) from 0 wt% to 1 wt%, the balance being nickel (Ni) and unavoidable impurities, for forming a Ni-based matrix alloy according to any of the preceding embodiments. In a preferred embodiment thereof, in the Ni-based powder composition, the Ni-based matrix alloy is a pre-alloyed powder.
In a particularly important aspect and embodiment of the present disclosure, the Ni-based powder composition and consequently, the Ni-based matrix alloy composition once formed, further comprise from 1 vol% to 70 vol% of a metal carbide powder comprising at least one metal carbide.
It is a major advantage of the Ni-based matrix alloys of the present disclosure that these can be formulated as pre-alloyed powders and desired amounts of metal carbide powders added, e.g., by in-mixing. This not only broadens the range and the composition of metal carbide powders, which can be added, making the hard-coatings independent on the formation chemistry of the constituent powders, but also it allows for lower deposition temperatures, since rather than providing coating temperatures necessary for metal carbide formation, it is now only necessary to provide energy for melting the Ni-based matrix alloy powder and not the metal carbides.
The actual concentration and composition of the metal carbide powder in the final Ni-based powder composition will normally be at the discretion of an end-user. However, in embodiments of the Ni-based matrix alloy composition the at least one metal carbide is selected from one or more of a nickel carbide, a chromium carbide, a vanadium carbide, a tungsten carbide (WC), a molybdenum carbide, a silicon carbide, a manganese carbide, an aluminum carbide, a titanium carbide, a niobium carbide, a tantalum carbide, a hafnium carbide, or a zirconium carbide, preferably is selected from one or more of a nickel carbide, a chromium carbide, a vanadium carbide, a tungsten carbide (WC), a molybdenum carbide, a silicon carbide, a manganese carbide, or an aluminum carbide, more preferably is selected from one or more of a nickel carbide, a chromium carbide, a vanadium carbide, a tungsten carbide (WC), or a molybdenum carbide.
It has however been established experimentally by the present inventors (c.f. below) that by thermal spraying of a Ni-based powder composition as detailed herein, it is possible to form the Ni-based matrix alloys of the present disclosure concomitantly with metal carbides of chromium, vanadium, tungsten, molybdenum, and when present in the Ni-based powder composition, also of silicon, manganese, and aluminum. The Ni-based matrix alloys then deposit from the gas-phase containing inclusions of the desired metal carbides.
Accordingly, there is herein disclosed a Ni-based powder composition consisting by total weight of the powder composition of chromium (Cr) 20 wt% - 30 wt%, vanadium (V) 5 wt% - 20 wt%, carbon (C) 2 wt% - 4 wt%, tungsten (W) 1 wt% - 10 wt%, molybdenum (Mo) 0.6 wt% - 10 wt%, silicon (Si) 0 wt% - 2 wt%, manganese (Mn) 0 wt% - 2 wt%, aluminum (Al) 0 wt% - 1 wt%, the balance being nickel (Ni) and unavoidable impurities.
In an embodiment thereof, a Ni-based powder composition, wherein chromium is present from 21 wt% to 29 wt%, from 22 wt% to 28 wt%, from 23 wt% to 27 wt%, or from 24 wt% to 26 wt%, preferably from 25 wt% to 30 wt%, from 26 wt% to 29 wt%, or from 27 wt% to 28 wt%.
In an embodiment thereof, a Ni-based powder composition, wherein vanadium is present from 6 wt% to 19 wt%, from 7 wt% to 18 wt%, from 8 wt% to 17 wt%, from 9 wt% to 16 wt%, from 10 wt% to 15 wt%, from 10 wt% to 14 wt%, or from 12 wt% to 13 wt%.
In an embodiment thereof, a Ni-based powder composition, wherein carbon is present from 2.3 wt% to 3.7 wt%, from 2.6 wt% to 3.4 wt%, or from 2.9 wt% to 3.1 wt%.
In an embodiment thereof, a Ni-based powder composition, wherein tungsten is present from 1 wt% to 9 wt%, from 2 wt% to 8 wt%, from 3 wt% to 7 wt%, or from 4 wt% to 6 wt%.
In an embodiment thereof, a Ni-based powder composition, wherein molybdenum is present from 1 wt% to 9 wt%, from 2 wt% to 8 wt%, from 3 wt% to 7 wt%, or from 4 wt% to 6 wt%.
In an embodiment thereof, a Ni-based powder composition, wherein molybdenum is present from 1 wt% to 9 wt%, from 2 wt% to 8 wt%, from 3 wt% to 7 wt%, or from 4 wt% to 6 wt%.
In an embodiment thereof, a Ni-based powder composition, wherein silicon is present in an amount of at least 0.1 wt%.
In an embodiment thereof, a Ni-based powder composition, wherein manganese is present in an amount of not more than 1.5 wt%, not more than 1.0 wt%, not more than 0.75 wt%, or not more than 0.5 wt%.
In an embodiment thereof, a Ni-based powder composition, wherein aluminum is present in an amount of not more than 0.75 wt%, or not more than 0.5 wt%.
In a preferred embodiment of the above Ni-based powder compositions there is herein detailed a Ni-based powder composition consisting by total weight of the powder composition of chromium (Cr) 25 wt% - 30 wt%, vanadium (V) 7 wt% - 13 wt%, carbon (C) 2 wt% - 3 wt%, tungsten (W) 3 wt% - 7 wt%, molybdenum (Mo) 3 wt% - 7 wt%, silicon (Si) 0.1 wt% - 2 wt%, aluminum (Al) 0 wt% - 1 wt%, the balance being nickel (Ni) and unavoidable impurities including manganese.
In a preferred embodiment of the above Ni-based powder compositions there is herein detailed a Ni-based powder composition consisting by total weight of the powder composition of chromium (Cr) 25 wt% - 30 wt%, vanadium (V) 13 wt% - 19 wt%, carbon (C) 3 wt% - 4 wt%, tungsten (W) 3 wt% - 7 wt%, molybdenum (Mo) 3 wt% - 7 wt%, silicon (Si) 0.1 wt% - 2 wt%, aluminum (Al) 0 wt% - 1 wt%, the balance being nickel (Ni) and unavoidable impurities including manganese.
In both of these preferred embodiments, the resulting Ni-based matrix alloys form as eutectics from the gas-phase, the formed eutectics being essentially devoid of carbon.

EXAMPLES

In experiments, the abovementioned two preferred embodiments of the Ni-based powder compositions were tested for their suitability for thermal spraying (e.g., HVOF or HVAF), surface welding (e.g., PTA welding or Laser Cladding) or Additive Manufacturing (e.g., Powder Bed Fusion or Direct Energy Deposition).
The resulting microstructure after thermal spraying was characterized by fine carbide precipitations as shown in the figures, embedded in a corrosion resistant Ni based matrix to resist mechanical wear and corrosion. The carbides such as Vanadium carbides and Chromium carbides (and mixed carbides) provide the necessary hard phases to resist mechanical wear like abrasion or erosion. The Ni based matrix is alloyed with elements such as Cr, Mo, W, Si and/or Al to provide solid solution strengthening and corrosion resistance. It is proved by similar alloys that the type and volume fraction of the hard phase precipitants provide an essential high resistance against mechanical wear (such as abrasion, sliding, erosion). The level of hard phases also influences the properties in terms of brittle nature at dynamics forces or crack-sensitivity in the application process. It is followed that the Ni based matrix provides some impact tolerance compared to existing solutions.
In figure 1 to 4 is shown comparative example using a Fe containing composition of Ni (bal.), Cr 16wt%, V 11wt%, W 4.0wt%, Mo 3.0wt%, C 2.5wt%, Fe 7.0wt%, which has been vacuum atomized with KVA.
As shown in Figure 1 the composition provides a corrosion resistant alloy with a high degree of melting with a target of 45 HRC by VC and eutectic precipitants. Figure 2 shows the composition with a 30-33 HRC as welded and was not considered relevant for further testing. In Figure 3 the composition has a hardness of approx. 700 HV0.3 as HVOF-sprayed and 33 HRC as welded, and there is some porosity due to unoptimized particle size distribution. In figure 4 is shown a salt spray testing of the composition of figure 3 where weakness in corrosion is seen due to open cavities and Cr depletion as result of oxidation.
In an experiment according to the present disclosure, the amount of Cr was increased, and Fe was avoided. An alloy composition of Ni (bal.), Cr 28wt%, V 9.0wt%, Mo 3.5wt%, C 2.5wt%, Al 0.0wt%, Si 0.0wt%, was provided as shown in figure 5 with higher Cr for improving corrosion resistance after thermal spraying. Mo is substituted for W which has a similar effect in solid solution strengthening but has a better corrosion resistance. Unknown large particles are formed which are unwanted. In Figure 6 is shown the composition of figure 5 which was HVOF sprayed, and shows large unwanted precipitants embedded in the coatings, the hardness is approx. 800 HV0.3. In Figure 7 is shown the composition of figure 5 as PTA welded and larger precipitants are seen, as well as needle-like precipitations giving an unwanted microstructure.
In an experiment according to the present disclosure, the amount of V was increased, and Cr was kept low and in figure 8 an alloy composition of Ni (bal.), Cr 14wt%, V 17wt%, Mo 1.0wt%, C 4.0wt%, Al 0.0wt%, Si 0.4wt%, was provided. As seen unknown large particles are present in the alloy. In figure 9 the composition of Figure 8 is shown after PTA welding and Laser cladding (LC), and here too large precipitants are formed. In figure 10 is shown the composition of figure 8 which was HVOF sprayed, and shows large unwanted precipitants embedded in the coatings, the hardness is approx. 800 HV0.3.
In Figure 11 is shown an alloy composition Ni (bal.), Cr 27wt%, V 10wt%, Mo 5.5wt%, C 2.5wt%, Al 0.4wt%, Si 0.2wt%, in the present context having a high Cr and medium V content. There is a homogeneous chemical distribution and no large unwanted precipitants. In Figure 12 is shown an alloy composition with Ni (bal.), Cr 28wt%, V 16wt%, Mo 5.7wt%, C 3.7wt%, Al 0.4wt%, Si 0.3wt%, in the present context having a high Cr and high V content.
Known alloys which are Fe-based and contain the risk of undesired phase transformation such as martensite or delta ferrite, or the risk of incomplete martensitic phase transformation which retains residual austenite while applying them with casting/thermal spraying/surface welding/AM, leading for example to undesired level of hardness or undesirable brittleness. It was found that the presently formed depositions were free of these risks because they stay in cubic phase from room temperature to liquefication so that the result in terms or mechanical properties is consistent.
The invented alloy is based on Ni, it always stays in FCC lattice and therefore an imbalance with hard HCP phase does not occur (c.f. "Amperweld Ni-CCA4 med Phase Simulation" with simulation results of such a Ni based alloy and the received stable FCC phase in comparison to a V and Cr-rich carbide strengthened Fe based alloys called AMPERWELD CCA4) . Hardness is gained by precipitating out fine hard phases such as Cr- and V-rich carbides so that the martensitic phase transformation is not needed. This has a simplifying effect on the powder atomization and the required window of the chemical composition. It was found that the Ni-based powders of the present disclosure were also independent to the processing technology and the characterizing cooling speed when it comes to the required hardness by martensitic phase transformation. Since the since the invention is hard phase strengthened, different cooling speeds will affect the size (and therefore the mean free path between the individual hard phases) of the precipitants.
In a ThermoCalc computer simulation, the boundaries of the present alloys were examined, using the data of Table 1 as starting data for the simulation on the Cr-rich and V-rich carbide strengthened Ni-based alloy, all elements in wt%. Table 1:

Elements Ni-Cr powder REF1 REF2

Ni balance balance balance

Cr 20-30 25-30 25-30

V 8-20 13-19 7-13

W 0-10 3-7 3-7

Mo 0-10 3-7 3-7

C 2-4 3-4 2-3
In ThermoCalc all calculations are performed with the assumption that the system is closed, and the material/phases are in equilibrium.
According to the phase calculation, the following phase compositions for REF1 (Table 2) and REF2 (Table 3) can be expected; Matrix alloy, FCC, M23C6, and HCP.

As desired, nickel does not present in the FCC and HCP phases (in the simulations to a total content below 0.1 wt%), rather nickel stays in the matrix alloy, and only to a smaller content (between 1.0 wt% to 8.5 wt%) contributes to the M23C6 hard phase. Thereby, also the simulation confirms the experiments that the high corrosion resistance is due to the advantageous distribution of nickel into the matrix alloy, when Ni-Cr-powders as detailed herein are melted.

Table 2 -2 Sample REF1

Results [wt%/part]		Total Composition	Ni	Cr	V	W	Mo	C
Matrix Alloy	MIN	60.8	72.4	15.2	0.3	1.6	0.8	0.0
Matrix Alloy	MAX	70.8	78.4	21.2	2.9	5.2	3.0	0.0
FCC	MIN	4.1	0.0	1.6	67.9	1.1	0.8	15.0
FCC	MAX	10.0	0.1	6.4	81.2	8.0	3.6	15.6
M23C6	MIN	20.6	1.2	55.5	5.4	5.1	10.3	4.8
M23C6	MAX	30.8	7.2	62.2	14.0	14.4	16.4	5.0
HCP	MIN	0.0	0.0	9.7	45.9	2.7	17.5	8.6
HCP	MAX	5.8	0.0	10.4	59.5	6.6	29.2	9.4

In the table, the phase-distribution is wt% based on totel weight of the composition, whereas the elements are listed based on their relative distribution in the respective phases.

Table 3 -Sample REF2

Results [wt%/part]		Total Composition	Ni	Cr	V	W	Mo	C
Matrix Alloy	MIN	61.4	72.1	14.9	0.3	2.0	1.0	0.0
Matrix Alloy	MAX	70.5	79.1	20.7	2.9	5.0	3.2	0.0
FCC	MIN	1.1	0.0	1.5	67.5	1.4	0.8	15.0
FCC	MAX	9.8	0.1	6.7	81.1	7.1	3.2	15.7
M23C6	MIN	20.7	1.1	54.3	4.7	4.3	10.3	4.8
M23C6	MAX	29.9	8.5	62.2	14.4	15.0	15.8	5.0
HCP	MIN	0.2	0.0	9.7	44.8	3.6	17.4	8.6
HCP	MAX	8.6	0.0	10.2	59.3	5.7	31.2	9.4

In the table, the phase-distribution is wt% based on total weight of the composition, whereas the elements are listed based on their relative distribution in the respective phases.

CLOSING COMMENTS

Although the present invention has been described in detail for purpose of illustration, it is understood that such detail is solely for that purpose, and variations can be made therein by those skilled in the art in practicing the claimed subject matter, from a study of the drawings, the disclosure, and the appended claims. The term "comprising" as used in the claims does not exclude other elements or steps. The indefinite article "a" or "an" as used in the claims does not exclude a plurality.

Claims

A Ni-based matrix alloy consisting by total weight of the alloy of: Chromium (Cr) 12 wt% - 23 wt%, Vanadium (V) 0.2 wt% - 3.1 wt%, Tungsten (W) 1.0 wt% - 6.0 wt%, Molybdenum (Mo) 0.6 wt% - 3.5 wt%,

and optionally Silicon (Si) 0 wt% - 2 wt%, Manganese (Mn) 0 wt% - 2 wt%, Aluminum (Al) 0 wt% - 1 wt%,

the balance being nickel (Ni) and unavoidable impurities.
A Ni-based matrix alloy according to claim 1, wherein chromium is present from 13 wt% to 22 wt%, from 14 wt% to 21 wt%, from 15 wt% to 20 wt%, from 16 wt% to 19 wt%, or from 17 wt% to 18 wt% in the Ni-based matrix alloy.
A Ni-based matrix alloy according to claim 1 or claim 2, wherein vanadium is present from 0.3 wt% to 3.0 wt%, from 0.4 wt% to 2.9 wt%, from 0.5 wt% to 2.8 wt%, from 0.6 wt% to 2.7 wt%, from 0.6 wt% to 2.7 wt%, from 0.7 wt% to 2.6 wt%, from 0.8 wt% to 2.5 wt%, from 0.9 wt% to 2.4 wt%, from 1.0 wt% to 2.3 wt%, from 1.2 wt% to 2.1 wt%, from 1.4 wt% to 1.9 wt%, or from 1.6 wt% to 1.7 wt% in the Ni-based matrix alloy.
A Ni-based matrix alloy according to any preceding claim, wherein tungsten is present from 1.5 wt% to 5.5 wt%, from 2.0 wt% to 5.0 wt%, from 2.5 wt% to 4.5 wt%, from 3.0 wt% to 4.0 wt%, or from 3.3 wt% to 3.7 wt% in the Ni-based matrix alloy.
A Ni-based matrix alloy according to any preceding claim, wherein molybdenum is present from 0.7 wt% to 3.4 wt%, from 0.8 wt% to 3.3 wt%, from 0.9 wt% to 3.2 wt%, from 1.0 wt% to 3.0 wt%, from 1.3 wt% to 2.7 wt%, from 1.6 wt% to 2.4 wt%, or from 1.8 wt% to 2.2 wt% in the Ni-based matrix alloy.
A Ni-based powder composition at least comprising: Chromium (Cr) 12 wt% - 23 wt%, Vanadium (V) 0.2 wt% - 3.1 wt%, Tungsten (W) 1.0 wt% - 6.0 wt%, Molybdenum (Mo) 0.6 wt% - 3.5 wt%, and optionally Silicon (Si) 0 wt% - 2 wt%, Manganese (Mn) 0 wt% - 2 wt%, Aluminum (Al) 0 wt% - 1 wt%,

the balance being nickel (Ni) and unavoidable impurities, for forming a Ni-based matrix alloy according to any of the preceding claims.
A Ni-based powder composition according to claim 6, wherein the Ni-based matrix alloy is a pre-alloyed powder.
A Ni-based powder composition according to any of the claims 6 or 7, further comprising from 1 vol% to 70 vol% of a metal carbide powder comprising at least one metal carbide.
A Ni-based powder composition according to claim 8, wherein the at least one metal carbide is selected from one or more of a nickel carbide, a chromium carbide, a vanadium carbide, a tungsten carbide (WC), a molybdenum carbide, a silicon carbide, a manganese carbide, an aluminum carbide, a titanium carbide, a niobium carbide, a tantalum carbide, a hafnium carbide, or a zirconium carbide, preferably is selected from one or more of a nickel carbide, a chromium carbide, a vanadium carbide, a tungsten carbide (WC), a molybdenum carbide, a silicon carbide, a manganese carbide, or an aluminum carbide, more preferably is selected from one or more of a nickel carbide, a chromium carbide, a vanadium carbide, a tungsten carbide (WC), or a molybdenum carbide.
A Ni-based powder composition consisting by total weight of the powder composition of: Chromium (Cr) 20 wt% - 30 wt%, Vanadium (V) 5 wt% - 20 wt%, Carbon (C) 2 wt% - 4 wt%, Tungsten (W) 1 wt% - 10 wt%, Molybdenum (Mo) 0.6 wt% - 10 wt%, Silicon (Si) 0 wt% - 2 wt%, Manganese (Mn) 0 wt% - 2 wt%, Aluminum (Al) 0 wt% - 1 wt%,

the balance being nickel (Ni) and unavoidable impurities.
A Ni-based powder composition according to claim 10, wherein chromium is present from 21 wt% to 29 wt%, from 22 wt% to 28 wt%, from 23 wt% to 27 wt%, or from 24 wt% to 26 wt%, preferably from 25 wt% to 30 wt%, from 26 wt% to 29 wt%, or from 27 wt% to 28 wt%.
A Ni-based powder composition according to claim 10 or claim 11, wherein vanadium is present from 6 wt% to 19 wt%, from 7 wt% to 18 wt%, from 8 wt% to 17 wt%, from 9 wt% to 16 wt%, from 10 wt% to 15 wt%, from 10 wt% to 14 wt%, or from 12 wt% to 13 wt%.
A Ni-based powder composition according to any of the claims 10 to 12, wherein carbon is present from 2.3 wt% to 3.7 wt%, from 2.6 wt% to 3.4 wt%, or from 2.9 wt% to 3.1 wt%.
A Ni-based powder composition according to any of the claims 10 to 13, wherein tungsten is present from 1 wt% to 9 wt%, from 2 wt% to 8 wt%, from 3 wt% to 7 wt%, or from 4 wt% to 6 wt%.
A Ni-based powder composition according to any of the claims 10 to 14, wherein molybdenum is present from 1 wt% to 9 wt%, from 2 wt% to 8 wt%, from 3 wt% to 7 wt%, or from 4 wt% to 6 wt%.
A Ni-based powder composition according to any of the claims 10 to 15, wherein molybdenum is present from 1 wt% to 9 wt%, from 2 wt% to 8 wt%, from 3 wt% to 7 wt%, or from 4 wt% to 6 wt%.
A Ni-based powder composition according to any of the claims 10 to 16, wherein silicon is present in an amount of at least 0.1 wt%.
A Ni-based powder composition according to any of the claims 10 to 17, wherein manganese is present in an amount of not more than 1.5 wt%, not more than 1.0 wt%, not more than 0.75 wt%, or not more than 0.5 wt%.
A Ni-based powder composition according to any of the claims 10 to 17, wherein aluminum is present in an amount of not more than 0.75 wt%, or not more than 0.5 wt%.