Method for evaluating solid solution amount of grain inhibitor in tungsten carbide powder

Abstract

The application discloses a kind of evaluation methods of grain inhibitor solid solution amount in tungsten carbide powder, by studying the variation of lattice constant of tungsten carbide carbon deficiency phase existing in tungsten carbide powder, solid solution phase formed by grain inhibitor and tungsten carbide carbon deficiency phase and WC phase, the change of grain inhibitor solid solution amount can be deduced, it has guiding significance to subsequent process: grain inhibitor that has been solid solution reduces the content of grain inhibitor in Co phase in subsequent process, theoretically weakens the inhibition effect, that is, the greater the solid solution amount of grain inhibitor in tungsten carbide powder, the worse the inhibition effect of grain inhibitor in subsequent process.Evaluation of grain inhibitor solid solution amount in tungsten carbide powder is beneficial to evaluate the influence of preparation process of tungsten carbide powder on solid solution amount, beneficial to evaluate the inhibition effect of grain inhibitor on subsequent process, and then evaluate the influence of tungsten carbide powder prepared by different processes on subsequent process, which is beneficial to more in-depth characterization of powder quality.

Description

Technical Field

[0001] This invention relates to the field of physicochemical testing technology, and more specifically, to a method for evaluating the amount of grain inhibitor solid solution in tungsten carbide powder. Background Technology

[0002] Ultrafine cemented carbide possesses superior properties that are incomparable to ordinary cemented carbide due to its combination of high hardness and high strength. The key technologies for its preparation lie in the raw material powder preparation process and the alloy sintering process, while inhibiting grain growth is the core research content for the preparation of ultrafine cemented carbide.

[0003] The addition of grain inhibitors is one way to suppress the growth of ultrafine cemented carbide grains. The inhibition mechanism during cemented carbide sintering has been extensively studied and discussed, including: ① adsorption: inhibitor elements adsorb onto the surface of tungsten carbide particles, reducing their dissolution rate in the liquid phase; ② dissolution: preferential dissolution of inhibitors in the Co phase reduces the solubility of tungsten carbide in the liquid phase; ③ segregation: inhibitors segregate along the WC / WC interface, hindering the migration of the tungsten carbide interface. However, the exact mechanisms of inhibition and their specific forms remain unclear.

[0004] Tungsten carbide powder, used as raw material, is prepared by carbonization of fine-particle tungsten oxide powder or tungsten powder with pre-added grain inhibitors. It is generally believed that the inhibitors dissolve into the WC phase or exist as an independent phase, but due to the small amount added, it is usually considered impossible to determine their solid solution content through detection methods. In actual production, only elemental analysis can be used to roughly determine its "content," which cannot provide more precise theoretical guidance for subsequent process control in cemented carbide production. Therefore, a method for evaluating the solid solution content of grain inhibitors in tungsten carbide powder is particularly necessary. Summary of the Invention

[0005] The purpose of this invention is to provide a method for evaluating the solid solution content of grain inhibitors in tungsten carbide powder, in order to solve the problem that in the current process of preparing ultrafine cemented carbide, it is impossible to determine the effect of adding grain inhibitors to tungsten carbide powder as raw material, and thus impossible to predict the powder quality.

[0006] This invention is implemented as follows:

[0007] In a first aspect, the present invention provides a method for evaluating the solid solubility of grain inhibitors in tungsten carbide powder, comprising: analyzing the X-ray diffraction patterns of a target tungsten carbide powder sample and a reference tungsten carbide powder obtained under the same testing equipment and testing conditions to obtain a solid solubility index G characterizing the total solid solubility of grain inhibitors in the target tungsten carbide powder sample, wherein the solid solubility index G = g1 + g2 + g3, and the larger the solid solubility index, the greater the solid solubility of grain inhibitors in the corresponding target tungsten carbide powder sample;

[0008] Where g1=(θ1-θ i1)×100%, the θ1 and θ i1 These are the α-phase peak positions corresponding to the target tungsten carbide powder sample and the reference tungsten carbide powder sample in the X-ray diffraction pattern, respectively.

[0009] g2=(θ2-θ i1 )×100%, the θ2 and θ i1 These are the β-phase peak positions of the target tungsten carbide powder sample and the α-phase peak positions of the reference tungsten carbide powder sample, respectively, in the X-ray diffraction pattern.

[0010] g3=(θ3-θ i3 )×100%, the θ3 and θ i3 These are the peak values ​​of WC(101) for the target tungsten carbide powder sample and the reference tungsten carbide powder sample, respectively, in the X-ray diffraction patterns.

[0011] The α phase is the carbon-deficient phase of tungsten carbide, and the β phase is a solid solution phase formed by the combination of grain inhibitor and carbon deficiency in tungsten carbide. No grain inhibitor was added during the preparation process of the reference tungsten carbide powder.

[0012] In an optional embodiment, the α-phase and / or β-phase crystal structure is an orthorhombic or hexagonal phase, and the lattice constant of the orthorhombic phase is... The lattice constant of the hexagonal phase

[0013] In an optional implementation, the peak value of the α phase is ∈ (40°-50°); and / or, the peak value of the β phase is ∈ (40°-50°); and / or, the peak value of the WC(101) is ∈ (50°-60°).

[0014] In an optional implementation, the test conditions are as follows: a Co target is used, the scanning angle includes 40°-50° and 50°-60°, the step size is 0.033°-0.035°, and the dwell time per step is 790s-810s.

[0015] In an optional implementation, the testing equipment is a PANalytical X'PERT PRO X-ray diffractometer.

[0016] In an optional embodiment, the analysis includes: using analysis software to obtain the peak position values ​​θ1, θ2 of the α phase and β phase of the target tungsten carbide powder sample and the peak position value θ3 of WC(101), and obtaining the peak position value θ3 of the α phase of the reference tungsten carbide powder sample. i1 And the peak value of WC(101) is θ i3 .

[0017] In an optional embodiment, the grain inhibitor is selected from carbides, oxides, or salts of transition metal elements, and the grain inhibitor is added during the preparation process of the target tungsten carbide powder sample.

[0018] In an optional embodiment, the grain inhibitor is selected from at least one of VC, Cr3C2, Mo2C, NbC, TaC, and TiC.

[0019] In an optional embodiment, the grain inhibitor is selected from V, Cr 、 Mo 、 At least one of the oxides or salts of Nb, Ta, and Ti.

[0020] In an optional embodiment, the Cr and V in the grain inhibitor form a limited substitution solid solution with WC.

[0021] The present invention has the following beneficial effects:

[0022] By studying the changes in the lattice constant of the carbon-deficient phase of tungsten carbide, the solid solution phase formed by the combination of grain inhibitors and carbon-deficient tungsten carbide in tungsten carbide powder, and the WC phase, the variation in the solid solution amount of grain inhibitors can be deduced, which has guiding significance for subsequent processes: the dissolved grain inhibitors reduce the content of grain inhibitors in the Co phase during subsequent sintering processes, theoretically weakening the inhibition effect. That is, the greater the solid solution amount of grain inhibitors in tungsten carbide powder, the worse the inhibition effect of grain inhibitors in subsequent processes. Evaluating the solid solution amount of grain inhibitors in tungsten carbide powder is beneficial for assessing the inhibition effect of grain inhibitors, for evaluating the influence of tungsten carbide powder preparation processes on the solid solution amount, and for evaluating the influence of tungsten carbide powders prepared by different processes on subsequent processes, which is conducive to a more in-depth characterization of powder quality. Attached Figure Description

[0023] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 The peak separation effect diagram of the α phase and β phase corresponding peaks in a target tungsten carbide powder sample;

[0025] Figure 2 The XRD patterns of each sample in Example 1 at 44°-48° are shown.

[0026] Figure 3 The image shows the XRD pattern of sample #2 after peak separation in Example 1.

[0027] Figure 4 The images show the XRD patterns of each sample in Example 2 at 44°-48°. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased commercially.

[0029] One embodiment of this application provides a method for evaluating the solid solution content of grain inhibitors in tungsten carbide powder.

[0030] This includes: analyzing the X-ray diffraction patterns of the target tungsten carbide powder sample and the reference tungsten carbide powder obtained under the same testing equipment and conditions to obtain the solid solubility index G, which characterizes the total solid solubility of the grain inhibitor in the target tungsten carbide powder sample. The solid solubility index G = g1 + g2 + g3. The larger the solid solubility index, the greater the solid solubility of the grain inhibitor in the corresponding target tungsten carbide powder sample.

[0031] Where g1=(θ1-θ i1 )×100%, the θ1 and θ i1 These are the α-phase peak positions corresponding to the target tungsten carbide powder sample and the reference tungsten carbide powder sample in the X-ray diffraction pattern, respectively.

[0032] g2=(θ2-θ i1 )×100%, the θ2 and θ i1 These are the β-phase peak positions of the target tungsten carbide powder sample and the α-phase peak positions of the reference tungsten carbide powder sample, respectively, in the X-ray diffraction pattern.

[0033] g3=(θ3-θ i3 )×100%, the θ3 and θ i3 These are the peak values ​​of WC(101) for the target tungsten carbide powder sample and the reference tungsten carbide powder sample, respectively, in the X-ray diffraction patterns.

[0034] The α phase is the carbon-deficient phase of tungsten carbide, and the β phase is a solid solution phase formed by the combination of grain inhibitor and carbon deficiency in tungsten carbide. No grain inhibitor was added during the preparation process of the reference tungsten carbide powder.

[0035] The current technology cannot determine the solid solution content of grain inhibitors in tungsten carbide because it ignores the carbon-deficient phase of tungsten carbide present in the tungsten carbide powder and the solid solution phase formed by the combination of grain inhibitors and carbon-deficient tungsten carbide. By studying the changes in the lattice constant of the carbon-deficient phase of tungsten carbide, the solid solution phase formed by the combination of grain inhibitors and carbon-deficient tungsten carbide, and the WC phase present in tungsten carbide powder, the change in the solid solution content of grain inhibitors can be deduced, which is of guiding significance for subsequent processes: the dissolved grain inhibitors reduce the content of grain inhibitors in the Co phase in subsequent processes, theoretically weakening the inhibition effect. That is, the greater the solid solution content of grain inhibitors in tungsten carbide powder, the worse the inhibition effect of grain inhibitors in subsequent processes. Evaluating the solid solution content of grain inhibitors in tungsten carbide powder is beneficial for assessing the inhibition effect of grain inhibitors, for evaluating the influence of tungsten carbide powder preparation process on the solid solution content, and for evaluating the influence of tungsten carbide powder prepared by different processes on subsequent processes. It is also beneficial for more in-depth characterization of powder quality, such as grain size. The solid solution index can be used to evaluate the solid solution effect of grain inhibitors in tungsten carbide powder. The larger the solid solution index, the more inhibitors are dissolved in the powder.

[0036] Typically, grain inhibitors are selected from carbides, oxides, or salts of transition metals. Because transition metals and tungsten have similar atomic radii, the likelihood of them forming an intermediate phase is low, while the likelihood of forming a substitutional solid solution is high. Considering that the main internal condition for isomorphic substitution is the properties of the ions (atoms) themselves, such as their radii, valence relationship, and ion type, the radii of the mutually substituting atoms or ions should be similar. If r1 and r2 represent the radii of the larger and smaller ions, respectively, then when (r1-r2) / r2 < 10-15%, complete isomorphic substitution generally occurs. In this application, the transition metal ions in the grain inhibitor do not meet the above requirements; therefore, in the system of this application, the transition metal and tungsten carbide may form a limited substitutional solid solution. Since the radii of transition metal ions such as Cr and V are smaller than those of W, if a substitutional solid solution phase is formed, the interplanar spacing d in the crystal structure will become smaller. According to Bragg's law, 2dsinθ=nλ, the smaller the d value, the larger the θ value. This is reflected in the diffraction pattern, that is, the greater the degree of solid solution, the larger the peak position value, and the diffraction peak shifts to the right.

[0037] Specifically, without the addition of grain inhibitors, only the α phase exists in tungsten carbide powder. After the addition of grain inhibitors, the β phase is generated, and its peak position 2θ value increases with the increase of the amount of grain inhibitor added, while the peak position value of the α phase changes less. Therefore, it is believed that the increase of the amount of grain inhibitor solid solution in tungsten carbide powder results in: ① a larger peak position value of the β phase, where the β phase is a solid solution phase formed by the combination of grain inhibitors and carbon deficiency in tungsten carbide; ② a small amount of transition metal in the grain inhibitor is solidly dissolved in the WC phase, which reduces its interplanar spacing and increases the peak position, thus increasing the peak position value of WC(101); ③ the grain inhibitor exacerbates the reduction of carbon content in tungsten carbide, which reduces its interplanar spacing and increases the peak position, thus increasing the peak position value of the carbon deficiency phase in tungsten carbide. That is, grain inhibitors reduce the amount of coordinated carbon in W, increase the content of the α phase, and increase the peak intensity of the corresponding diffraction peak. The reduction of carbon content may also form non-stoichiometric carbon deficiency phases, which will also increase the peak position value of the α or β phase. Therefore, by comparing the peak values ​​of the α phase, the β phase, or the WC(101) in two samples, the solid solution content of grain inhibitors in the α phase, β phase, and WC phase can be estimated respectively, which is beneficial for studying the affinity and solid solution degree of grain inhibitors in the α phase, β phase, and WC phase respectively.

[0038] In an optional implementation, the higher the solid solution index, the greater the amount of grain inhibitor dissolved in the corresponding target tungsten carbide powder sample.

[0039] It should be noted that the peak positions of the α-phase, β-phase, and WC-phase in tungsten carbide powder samples are affected by both the preparation method and the grain inhibitor. Therefore, when evaluating the solid solution content, ideally, the target tungsten carbide powder sample and the reference tungsten carbide powder sample should be prepared using the same method, mainly including identical process parameters such as temperature and holding time. In some cases, to improve the accuracy of the comparison, the difference between the target tungsten carbide powder sample and the reference tungsten carbide powder sample may only be the type and amount of grain inhibitor added. This allows for the study of the impact of the type and amount of grain inhibitor added on subsequent processes, and more specifically, the study of the distribution of grain inhibitor in different phases such as α-phase, β-phase, and WC-phase, as well as the impact of the distribution of grain inhibitor in different phases on subsequent processes. In some embodiments, two samples with the same type and amount of grain inhibitor added but different steps in the preparation method can be selected to compare the impact of the preparation method on the solid solution effect.

[0040] In an optional embodiment, the α-phase and / or β-phase crystal structure is an orthorhombic or hexagonal phase, and the lattice constant of the orthorhombic phase is... The lattice constant of the hexagonal phase

[0041] In an optional implementation, the peak value of the α phase is ∈ (40°-50°); and / or, the peak value of the β phase is ∈ (40°-50°); and / or, the peak value of the WC(101) is ∈ (50°-60°).

[0042] In an optional implementation, the test conditions are as follows: a Co target is used, the scanning angle includes 40°-50° and 50°-60°, the step size is 0.033°-0.035°, and the dwell time per step is 790s-810s.

[0043] In an optional implementation, the testing equipment is a PANalytical X'PERT PRO X-ray diffractometer.

[0044] In an optional embodiment, the analysis includes: using analysis software to obtain the peak position values ​​θ1, θ2 of the α phase and β phase of the target tungsten carbide powder sample and the peak position value θ3 of WC(101), and obtaining the peak position value θ3 of the α phase of the reference tungsten carbide powder sample. i1 And the peak value of WC(101) is θ i3 .

[0045] In some embodiments, the method for evaluating the amount of grain inhibitor solid solution in tungsten carbide powder includes the following steps:

[0046] 1. Sample preparation: Lightly grind the tungsten carbide powder sample, spread the sample flat on a conventional amorphous glass slide with a hollow groove, and flatten it.

[0047] 2. Test conditions: Co target, scanning angles 40-50° and 50-60°, step size 0.033°, dwell time 800s per step. The measuring instrument was a PANalytica lX'PERT PRO X-ray diffractometer. The diffraction patterns of the α and β phases were obtained at 40-50°, and the diffraction pattern of the WC phase was obtained at 50-60°.

[0048] 3. Testing: Take the target tungsten carbide powder sample and the reference tungsten carbide powder sample and test them under the same test conditions to obtain X-ray diffraction patterns.

[0049] 4. Analysis: Peak positions θ1 and θ2 of the α and β phases in the target tungsten carbide powder sample were obtained using analysis software for peak separation and fitting, and peak position θ3 of WC(101) was obtained. The peak separation effect is as follows: Figure 1 The WC(101) peak position value θ of the reference tungsten carbide powder sample without added grain inhibitor was obtained. i3 The peak value of the α phase is θ i1 No β phase.

[0050] Calculate the solid solution content using a benchmarking evaluation method:

[0051] ① Solid solution factor g1=(θ1-θ i1 )×100%;

[0052] ② Solid solution factor g2=(θ2-θ i1 )×100%;

[0053] ③ Solid solution factor g3=(θ3-θ i3 )×100%;

[0054] The solid solution index G = g1 + g2 + g3.

[0055] In an optional embodiment, the grain inhibitor is selected from carbides, oxides, or salts of transition metal elements, and the grain inhibitor is added during the preparation process of the target tungsten carbide powder sample.

[0056] In an optional embodiment, the grain inhibitor is selected from at least one of oxides or salts of V, Cr, Mo, Nb, Ta, and Ti.

[0057] In an optional embodiment, the grain inhibitor is selected from at least one of VC, Cr3C2, Mo2C, NbC, TaC, and TiC. Preferably, the grain inhibitor is VC or Cr3C2.

[0058] In an optional embodiment, the Cr and V in the grain inhibitor form a limited substitution solid solution with WC.

[0059] Taking grain suppressants VC or Cr3C2 as examples, W, Cr, and V are all transition elements in the periodic table. W and Cr belong to Group VIB, and V belongs to Group VB. The atomic radius of W is 0.202 nm, that of Cr is 0.185 nm, and that of V is 0.192 nm. Due to the similar atomic radii of W, Cr, and V, the possibility of them forming intermediate phases is relatively small, while the possibility of forming substitutional solid solutions is relatively high. In the compound, W mainly exists as W0. 6+ When Cr coordinates with Group V and Group VI ions, the ionic radius is 0.51-0.60 nm; when Cr coordinates with Group V and Group VI ions, the ionic radii of different valence states are 0.44-0.8 nm; when V coordinates with Group V and Group VI ions, the ionic radii of different valence states are 0.46-0.79 nm. According to the aforementioned theory, when Cr, V, and W combine with C to form a solid solution phase, they cannot form a completely isomorphous solid solution, but only a limited substitutional solid solution. Since the radii of Cr and V are both smaller than those of W, if a substitutional solid solution phase is formed, the interplanar spacing d in the crystal structure will decrease. According to Bragg's law, 2dsinθ = nλ, the smaller the d value, the larger the θ value. This is reflected in the diffraction pattern, that is, the greater the degree of solid solution, the larger the peak position value, and the diffraction peak shifts to the right.

[0060] Both the target tungsten carbide powder sample and the reference tungsten carbide powder of this invention are commercially available. The target tungsten carbide powder sample is typically prepared by adding a grain inhibitor to fine-particle tungsten oxide powder or tungsten powder before carbonization; the reference tungsten carbide powder was prepared without adding a grain inhibitor.

[0061] The features and performance of the present invention will be further described in detail below with reference to embodiments.

[0062] Example 1

[0063] Commercially available tungsten carbide powder was selected as samples 1-4 for testing. Sample 1 was prepared without the addition of grain inhibitors, while the amount of grain inhibitor added to samples 2-4 gradually increased. (The spectral comparison is shown below.) Figure 2 The results are shown in Table 1. (From...) Figure 2 As shown in Table 1, ① the powder without added grain inhibitor has no β phase; ② after adding grain inhibitor, the β phase appears, and as the amount of grain inhibitor added increases, the α peak position does not change much, but the β peak position increases significantly, and the WC(101) peak position increases significantly; ③ sample #2 appears to be a single peak, but through peak splitting ( Figure 3 It can be seen that it is actually an overlapping peak of α phase and β phase.

[0064] Table 2 shows the solid solution factor and solid solution index of samples 2#-4# relative to sample 1# in this embodiment. Table 2 shows that for samples 2#-4#, the degree of solid solubility of the grain inhibitor increases, and the solid solution index also increases, which is consistent with the trend of the amount of inhibitor added, indicating the reliability of the method. Furthermore, the solid solution factor shows that this inhibitor has the best affinity for β and the highest degree of solid solubility.

[0065] Tungsten carbide powder and Co powder were mixed in the samples to be tested in Example 2#-4# of this embodiment to obtain cemented carbide. The grain size of the alloy was measured according to GB / T 3488.2-2018 / ISO 4499-2:2008 "Metallographic determination of microstructure of cemented carbide - Part 2: Measurement of WC grain size". The results showed that the grain size variation trend was the same as the solid solution index variation trend.

[0066] Table 1

[0067]

[0068] Table 2

[0069] Sample number Solid solution factor g1 Solid solution factor g2 Solid solution factor g3 Solid solution index G 1# 0 0 0 0 2# 1.90 20.90 0.28 23.08 3# 0.40 27.40 1.03 28.83 4# 1.70 31.40 1.70 34.80

[0070] Example 2

[0071] Commercially available tungsten carbide powder was selected as the test samples 1#-1 to 6#-1. The corresponding spectra of each sample are compared as follows: Figure 4 Table 3 shows the comparison of inhibitor addition amounts and results.

[0072] Depend on Figure 4 As shown in Table 3, ① tungsten carbide powder without grain inhibitor has no β phase; ② after adding grain inhibitor, β phase appears in tungsten carbide powder, and the position of β peak increases with the amount of grain inhibitor added.

[0073] The solid solution factors and solid solution indices are shown in Table 4. As can be seen from the solid solution factors, VC and Cr3C2, as grain inhibitors, have the best affinity for β and the highest degree of solid solubility.

[0074] Table 3

[0075]

[0076] Table 4 Solid Solution Index

[0077] Sample number Solid solution factor g1 Solid solution factor g2 Solid solution factor g3 Solid solution index G 1#-1 0 0 0 0 2#-1 -1.07 60.77 5.61 65.31 3#-1 1.27 58.57 6.57 66.41 4#-1 4.67 50.23 4.97 59.87 5#-1 7.16 49.07 5.61 61.84 6#-1 4.51 55.93 5.35 65.79

[0078] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for evaluating the solid solution content of grain inhibitors in tungsten carbide powder, characterized in that, include: The X-ray diffraction patterns of the target tungsten carbide powder sample and the reference tungsten carbide powder sample obtained under the same testing equipment and conditions were analyzed to obtain the solid solubility index G, which characterizes the total solid solubility of the grain inhibitor in the target tungsten carbide powder sample. The solid solubility index G = g1 + g2 + g3. Where g1=(θ1-θ i1 )×100%, the θ1 and θ i1 These are the α-phase peak positions corresponding to the target tungsten carbide powder sample and the reference tungsten carbide powder sample in the X-ray diffraction pattern, respectively. The larger the solid solution index, the greater the amount of grain inhibitor dissolved in the corresponding target tungsten carbide powder sample. g2=(θ2-θ i1 )×100%, the θ2 and θ i1 These are the β-phase peak positions of the target tungsten carbide powder sample and the α-phase peak positions of the reference tungsten carbide powder sample, respectively, in the X-ray diffraction pattern. g3=(θ3-θ i3 )×100%, the θ3 and θ i3 These are the peak values ​​of WC(101) for the target tungsten carbide powder sample and the reference tungsten carbide powder sample, respectively, in the X-ray diffraction patterns. The α phase is the carbon-deficient phase of tungsten carbide, and the β phase is a solid solution phase formed by the combination of grain inhibitor and carbon deficiency in tungsten carbide. No grain inhibitor was added during the preparation process of the reference tungsten carbide powder.

2. The method for evaluating the solid solution content of grain inhibitors in tungsten carbide powder according to claim 1, characterized in that, The α-phase and / or β-phase crystal structure is orthorhombic or hexagonal, and the lattice constant of the orthorhombic phase is... The lattice constant of the hexagonal phase 3. The method for evaluating the solid solution content of grain inhibitors in tungsten carbide powder according to claim 1, characterized in that, The peak value of the α phase is ∈ (40°-50°); and / or, the peak value of the β phase is ∈ (40°-50°); and / or, the peak value of the WC(101) is ∈ (50°-60°).

4. The method for evaluating the solid solution content of grain inhibitors in tungsten carbide powder according to claim 1, characterized in that, The test conditions are as follows: a Co target is used, the scanning angle includes 40°-50° and 50°-60°, the step size is 0.03°-0.035°, and the dwell time per step is 790s-810s.

5. The method for evaluating the solid solution content of grain inhibitors in tungsten carbide powder according to claim 1, characterized in that, The testing equipment was a PANalytical X'PERT PRO X-ray diffractometer.

6. The method for evaluating the solid solution content of grain inhibitors in tungsten carbide powder according to claim 1, characterized in that, The analysis includes: using analysis software to obtain the peak position values ​​θ1, θ2 of the α phase and β phase of the target tungsten carbide powder sample and the peak position value θ3 of WC(101), and obtaining the peak position value θ3 of the α phase of the reference tungsten carbide powder sample. i1 And the peak value of WC(101) is θ i3 .

7. The method for evaluating the solid solution content of grain inhibitors in tungsten carbide powder according to claim 1, characterized in that, The grain inhibitor is selected from carbides, oxides, or salts of transition metal elements, and is added during the preparation of the target tungsten carbide powder sample.

8. The method for evaluating the solid solution content of grain inhibitors in tungsten carbide powder according to claim 7, characterized in that, The grain inhibitor is selected from at least one of VC, Cr3C2, Mo2C, NbC, TaC, and TiC.

9. The method for evaluating the solid solution content of grain inhibitors in tungsten carbide powder according to claim 7, characterized in that, The grain inhibitor is selected from at least one of oxides or salts of V, Cr, Mo, Nb, Ta, and Ti.

10. The method for evaluating the solid solution content of grain inhibitors in tungsten carbide powder according to claim 8 or 9, characterized in that, The Cr and V in the grain inhibitor form a limited substitution solid solution with WC.

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