A BN-Al-ZrB2-TiC composite material, a preparation method thereof and application thereof in PcBN cutters

Abstract

The application provides a BN-Al-ZrB2-TiC composite material and a preparation method and application in PcBN cutters thereof, and belongs to the technical field of ceramic materials. The application adopts cBN, Al powder, ZrB2 and TiC as raw materials, mixes and grinds the raw materials, and then sintering under high temperature and high pressure, so that the raw materials react with each other, Al gradually dissolves, wets the surface of cBN particles, plays an activation role, promotes the reaction, and AlN generated by the reaction inhibits the phase transition of cBN to hBN; ZrB2 and TiC have high strength, high hardness and high wear resistance, and the two react to produce a solid solution, promote the densification of the ceramic material, refine the grain size, and improve the performance of the PcBN cutter BN-Al-ZrB2-TiC composite material.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of ceramic materials, in particular to a BN-Al-ZrB2-TiC composite material, a preparation method thereof and application of the composite material in a PcBN cutter. BACKGROUND

[0002] With the continuous development of modern technology and heavy industry, more and more high-strength, high-hardness and difficult-to-machine materials are widely used in various industrial productions. These materials, although having excellent properties, also bring many challenges in the machining process. Therefore, in this industrial background, it is particularly important to choose the right cutter, and the correct cutter selection can achieve higher material removal rate and make the machining process more efficient. For traditional cutting tools, there are often defects such as poor wear resistance, low thermal stability, and limited cutting speed in the machining process. Therefore, they perform poorly when machining high-strength or high-hardness materials, often requiring frequent replacement, increasing production costs and downtime. At the same time, traditional cutters are strongly dependent on cutting fluid, which also brings challenges in environmental protection and cost control.

[0003] Cubic boron nitride (cBN) is a material with hardness and wear resistance second only to diamond, and has more excellent thermal stability and chemical stability than diamond. By combining cubic boron nitride (cBN) with an appropriate amount of binder, polycrystalline cubic boron nitride (PcBN) is prepared under high temperature and high pressure. As a new type of cutter material, PcBN cutter, with its own advantages of high hardness, high wear resistance, high toughness and thermal stability, has become the most promising cutter material after artificial diamond, and the research and development of PcBN cutter is one of the keys to realize high-speed and high-precision cutting of difficult-to-machine materials. However, the current PcBN cutter has defects such as single binder system, excessive hardness and insufficient toughness. SUMMARY

[0004] The purpose of the present application is to provide a BN-Al-ZrB2-TiC composite material, a preparation method thereof and application of the composite material in a PcBN cutter, to solve the problem of single binder system, excessive hardness and insufficient toughness in the PcBN cutter.

[0005] In order to achieve the above-mentioned purpose of the application, the present application provides the following technical solutions:

[0006] The present application provides a preparation method of a BN-Al-ZrB2-TiC composite material, comprising the following steps:

[0007] Mixing zirconium boride and titanium carbide to obtain a first mixture;

[0008] The first mixed material is mixed with cubic boron nitride, aluminum powder and a solvent to obtain a second mixed material, and then ball milling, drying and sieving are sequentially performed on the second mixed material;

[0009] The second mixed material is subjected to sectional pressure sintering to obtain a BN-Al-ZrB2-TiC composite material.

[0010] Preferably, the molar ratio of the zirconium boride to the titanium carbide is 1:0.6-1.4, and the first mixing time is 15-45 min.

[0011] Preferably, the mass ratio of the cubic boron nitride, the aluminum powder to the first mixed material is 50-80:6:14-44.

[0012] Preferably, the ball milling is performed at a rotation speed of 80-200 r / min for 360-840 min, and the ball-to-material ratio is 2-5:1.

[0013] Preferably, the drying is performed at a temperature of 60-100 ℃ for 16-30 h, and the mesh size of the sieve used for sieving is 100-400 mesh.

[0014] Preferably, the sectional pressure sintering is performed by using a cubic press, and the pressure applied by the cubic press is 4-7 GPa.

[0015] Preferably, the sectional pressure sintering comprises: a first stage at a temperature of 900-1400 ℃ for 1-3 min, and the temperature is raised from room temperature to the temperature of the first stage at a rate of 300-500 ℃ / min; and a second stage at a temperature of 1500-2000 ℃ for 5-10 min, and the temperature is raised from the temperature of the first stage to the temperature of the second stage at a rate of 300-500 ℃ / min.

[0016] The application provides a BN-Al-ZrB2-TiC composite material prepared by the preparation method.

[0017] The application provides an application of the BN-Al-ZrB2-TiC composite material in a PcBN cutter.

[0018] The application provides a preparation method of BN-Al-ZrB2-TiC composite material, which uses cBN powder, Al powder, ZrB2 powder and TiC powder as raw materials, uses cBN as a matrix, and uses Al, ZrB2 and TiC as a binder phase, so that the single problem of the binder system is solved; during the sintering process under high temperature and high pressure, the raw materials react with each other, the binder phase is uniformly distributed between the cubic boron nitride particles, Al has good toughness as a metal, and the addition of Al as a binder is beneficial to improving the problem that the hardness of the tool is sufficient but the toughness is insufficient. Secondly, Al gradually dissolves during the sintering process, enters the intergranular gap to play a role in gap filling and promote the densification of the material, and wets the surface of the cBN particles to play an activation role and promote the reaction, and the generated AlN inhibits the phase transition of cBN to hBN; and ZrB2-TiC as a reinforcing phase, ZrB2 and TiC have high strength, high hardness and high wear resistance, the reinforcing phase ZrB2 and TiC partially react, on the one hand, the reaction generates titanium boride and zirconium carbide with small particles, the size of the particles is smaller, the distribution is more uniform, and the pores between the composite material particles can be better filled, and the small size grains can improve the hardness and bending strength of the material; on the other hand, part of the solid solution is generated, the ceramic material is sintered and densified, the grain size is refined, and the strength, hardness and wear resistance of the material are improved. The mechanical bonding of the traditional binder makes the tool prone to defects such as chipping and cracking during machining. Therefore, the BN-Al-ZrB2-TiC composite material has great advantages in high-speed cutting and other cutting processes, is also efficient and environmentally friendly, and belongs to the PcBN tool composite material with high strength and good toughness. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 It is the XRD result of the BN-Al-ZrB2-TiC composite material in Example 2.

[0020] Figure 2 It is the SEM image of the sintered raw material after ball milling in Example 2.

[0021] Figure 3 It is the surface morphology of the BN-Al-ZrB2-TiC composite material prepared in Example 1.

[0022] Figure 4 It is the fracture morphology of the BN-Al-ZrB2-TiC composite material prepared in Example 2.

[0023] Figure 5 It is the bending strength curve of the BN-Al-ZrB2-TiC composite material prepared in Example 3.

[0024] Figure 6 It is the Vickers hardness curve of the BN-Al-ZrB2-TiC composite material prepared in Example 3. DETAILED DESCRIPTION

[0025] In the present application, the required raw materials or reagents are commercially available unless otherwise specified.

[0026] The present application provides a preparation method of BN-Al-ZrB2-TiC composite material, comprising the following steps:

[0027] The zirconium boride and titanium carbide are first mixed to obtain a first mixed material;

[0028] The first mixed material, cubic boron nitride, aluminum powder and solvent are second mixed, and then sequentially subjected to ball milling, drying and sieving to obtain a second mixed material;

[0029] The second mixed material is subjected to segmented pressure sintering to obtain the BN-Al-ZrB2-TiC composite material.

[0030] The present application first mixes the zirconium boride and titanium carbide to obtain a first mixed material.

[0031] In the present application, the molar ratio of the zirconium boride and titanium carbide is preferably 1:0.6-1.4, further preferably 1:0.8-1.2, and more preferably 1:0.9-1; and the first mixing time is preferably 15-45 min, further preferably 20-40 min, and more preferably 25-30 min.

[0032] After obtaining the first mixed material, the present application second mixes the first mixed material, cubic boron nitride, aluminum powder and solvent, and then sequentially subjects them to ball milling, drying and sieving to obtain a second mixed material.

[0033] In the present application, the particle sizes of the zirconium boride, titanium carbide, cubic boron nitride and aluminum powder are micron level.

[0034] In the present application, the solvent is preferably anhydrous ethanol; and the present application does not have special limitation on the amount of the solvent, which can be adjusted according to actual needs to ensure that the grinding is completed.

[0035] In the present application, the mass ratio of the cubic boron nitride, aluminum powder and first mixed material is preferably 50-80:6:14-44, further preferably 55-75:6:19-39, and more preferably 60-70:6:24-34.

[0036] The present application does not have special limitation on the second mixing, which can be uniformly mixed according to the process well known in the art.

[0037] In the present application, the rotation speed of the ball mill is preferably 80-200 r / min, further preferably 120-160 r / min, and more preferably 140-150 r / min; the time is preferably 360-840 min, further preferably 480-720 min, and more preferably 540-640 min; and the ball-to-material ratio is preferably 2-5:1, further preferably 2.5-4.5:1, and more preferably 3-4:1.

[0038] In the present application, the drying temperature is preferably 60-100℃, further preferably 70-90℃, and more preferably 75-80℃; the time is preferably 16-30 h, further preferably 18-28 h, and more preferably 24-26 h; and the mesh size of the screen used for sieving is preferably 100-400 mesh, further preferably 150-350 mesh, and more preferably 200-300 mesh.

[0039] After obtaining the second mixture, the present application performs segmented pressure sintering on the second mixture to obtain a BN-Al-ZrB2-TiC composite material.

[0040] The present application preferably uses a cubic press to perform the segmented pressure sintering; and the pressure applied by the cubic press is preferably 4-7 GPa, further preferably 4.5-6 GPa, and more preferably 5-5.5 GPa.

[0041] In the present application, the segmented pressure sintering preferably comprises: a first stage with a temperature of 900-1400℃, a holding time of 1-3 min, and a temperature rising rate of 300-500℃ / min from room temperature to the temperature of the first stage; and a second stage with a temperature of 1500-2000℃, a holding time of 5-10 min, and a temperature rising rate of 300-500℃ / min from the temperature of the first stage to the temperature of the second stage.

[0042] In the present application, the temperature of the first stage is more preferably 1000-1300℃, and further preferably 1100-1200℃; the temperature rising rate from room temperature to the temperature of the first stage is more preferably 350-450℃ / min, and further preferably 380-400℃ / min; and the holding time of the first stage is more preferably 1.5-2.5 min, and further preferably 1.8-2.0 min.

[0043] The temperature of the second stage is more preferably 1500-1800℃, and further preferably 1550-1600℃; the temperature rising rate from the temperature of the first stage to the temperature of the second stage is more preferably 350-450℃ / min, and further preferably 380-400℃ / min; and the holding time of the second stage is more preferably 6-9 min, and further preferably 7-8 min.

[0044] After the segmented pressure sintering is completed, the present application is naturally cooled to room temperature to obtain the BN-Al-ZrB2-TiC composite material.

[0045] The present application provides the BN-Al-ZrB2-TiC composite material prepared by the preparation method.

[0046] The present application provides the application of the BN-Al-ZrB2-TiC composite material in the PcBN cutter. The method for the application is not specially limited, and the application according to the method well known in the art can be used.

[0047] The technical solutions provided by the present application will be described in detail below in combination with examples, but they should not be understood as limitations to the protection scope of the present application.

[0048] In the following examples, the particle sizes of the zirconium boride, titanium carbide, cubic boron nitride and aluminum powder are 1-3 μm, 1-2 μm, 2-4 μm and 1 μm respectively.

[0049] Example 1

[0050] 1) 24 g of zirconium boride and titanium carbide powders are mixed according to the proportion of 1:1 in mole ratio, and the mixing time is 30 min to obtain the mixed powder;

[0051] 2) 70 g of cubic boron nitride powder, 6 g of aluminum powder and 24 g of the mixed powder of zirconium boride and titanium carbide are added into a ball mill tank, 150 g of anhydrous ethanol is added, a planetary ball mill is used for ball milling, the ball-to-material ratio is 3:1, the rotation speed is 150 r / min, and the mixing time is 640 min, so as to obtain the sintering raw material;

[0052] 3) the sintering raw material is dried at 80℃ under vacuum for 24 h, and the dried sintering raw material is passed through a 300 mesh screen;

[0053] 4) the dried sintering raw material is filled into a graphite mold, and then sintering is performed by using a six-surface press, the temperature is increased from room temperature to 1200℃ at a rate of 400℃ / min while gradually increasing the pressure, and then the temperature is increased to 1600℃ at a rate of 400℃ / min, at this time, the maximum sintering pressure of 5.5 GPa is maintained for 8 min, and then the temperature is naturally cooled to room temperature to obtain the BN-Al-ZrB2-TiC composite material.

[0054] Example 2

[0055] 1) 24 g of zirconium boride and titanium carbide powders are mixed according to the proportion of 1:1 in mole ratio, and the mixing time is 30 min to obtain the mixed powder;

[0056] 2) 70 g cubic boron nitride powder, 6 g aluminum powder, 24 g zirconium boride and titanium carbide mixed powder were added into a ball mill tank, 150 g anhydrous ethanol was added, a planetary ball mill was used for ball milling, the ball-to-material ratio was 3:1, the rotation speed was 150 r / min, and the mixing time was 640 min, thereby obtaining a sintering raw material;

[0057] 3) The sintering raw material was vacuum dried at 80°C for 24 h, and the dried sintering raw material was passed through a 300 mesh screen;

[0058] 4) The dried sintering raw material was loaded into a graphite mold, and then sintering was performed using a six-surface press, while gradually increasing the pressure, the temperature was increased from room temperature to 1200°C at a rate of 400°C / min and maintained for 2 min, then increased to 1500°C at a rate of 400°C / min, at this time, the maximum sintering pressure of 5.5 GPa was maintained for 8 min, and then naturally cooled to room temperature, thereby obtaining a BN-Al-ZrB2-TiC composite material.

[0059] Example 3

[0060] 1) 24 g of zirconium boride and titanium carbide powder was mixed according to the molar ratio of 1:1, the mixing time was 30 min, and the mixed powder was obtained;

[0061] 2) 70 g cubic boron nitride powder, 6 g aluminum powder, 24 g zirconium boride and titanium carbide mixed powder were added into a ball mill tank, 150 g anhydrous ethanol was added, a planetary ball mill was used for ball milling, the ball-to-material ratio was 3:1, the rotation speed was 150 r / min, and the mixing time was 640 min, thereby obtaining a sintering raw material;

[0062] 3) The sintering raw material was vacuum dried at 80°C for 24 h, and the dried sintering raw material was passed through a 300 mesh screen;

[0063] 4) The dried sintering raw material was loaded into a graphite mold, and then sintering was performed using a six-surface press, while gradually increasing the pressure, the temperature was increased from room temperature to 1200°C at a rate of 400°C / min and maintained for 2 min, then increased to 1550°C at a rate of 400°C / min, at this time, the maximum sintering pressure of 5 GPa was maintained for 8 min, and then naturally cooled to room temperature, thereby obtaining a BN-Al-ZrB2-TiC composite material.

[0064] Example 4

[0065] 1) 24 g of zirconium boride and titanium carbide powder was mixed according to the molar ratio of 1:0.8, the mixing time was 30 min, and the mixed powder was obtained;

[0066] 2) 70 g of cubic boron nitride powder, 6 g of aluminum powder, 24 g of zirconium boride and titanium carbide mixed powder were added into a ball mill tank, 150 g of anhydrous ethanol was added, a planetary ball mill was used for ball milling, the ball-to-material ratio was 3:1, the rotation speed was 150 r / min, and the mixing time was 640 min, thereby obtaining a sintering raw material;

[0067] 3) The sintering raw material was dried at 80°C for 24 h under vacuum, and the dried sintering raw material was passed through a 300-mesh screen;

[0068] 4) The dried sintering raw material was loaded into a graphite mold, and then sintering was performed using a cubic press, gradually increasing the pressure while increasing the temperature from room temperature to 1100°C at a rate of 400°C / min for 2 min, and then increasing the temperature to 1600°C at a rate of 400°C / min, at which time the maximum sintering pressure of 5.5 GPa was maintained for 8 min, and then naturally cooled to room temperature, thereby obtaining a BN-Al-ZrB2-TiC composite material.

[0069] Example 5

[0070] 1) 24 g of zirconium boride and titanium carbide powder was mixed according to a molar ratio of 1:0.8, and the mixing time was 30 min, thereby obtaining a mixed powder;

[0071] 2) 70 g of cubic boron nitride powder, 6 g of aluminum powder, 24 g of zirconium boride and titanium carbide mixed powder were added into a ball mill tank, 150 g of anhydrous ethanol was added, a planetary ball mill was used for ball milling, the ball-to-material ratio was 3:1, the rotation speed was 150 r / min, and the mixing time was 640 min, thereby obtaining a sintering raw material;

[0072] 3) The sintering raw material was dried at 80°C for 16 h under vacuum, and the dried sintering raw material was passed through a 300-mesh screen;

[0073] 4) The dried sintering raw material was loaded into a graphite mold, and then sintering was performed using a cubic press, gradually increasing the pressure while increasing the temperature from room temperature to 1200°C at a rate of 350°C / min for 3 min, and then increasing the temperature to 1600°C at a rate of 350°C / min, at which time the maximum sintering pressure of 6 GPa was maintained for 7 min, and then naturally cooled to room temperature, thereby obtaining a BN-Al-ZrB2-TiC composite material.

[0074] Characterization and performance test

[0075] Figure 1 The XRD results of the BN-Al-ZrB2-TiC composite material in Example 2 are shown in FIG. 2. Figure 1 As can be seen from FIG. 2, ZrB2 and TiC react to form TiB2, ZrC and (Zr, Ti)C.

[0076] Figure 2 SEM image of sintered raw material after ball milling in Example 2; from Figure 2 It can be seen that the raw material is uniformly distributed after ball milling and no agglomeration occurs.

[0077] Figure 3 Surface morphology image of BN-Al-ZrB2-TiC composite material prepared in Example 1; from Figure 3 It can be seen that the binder is distributed around the cBN particles.

[0078] Figure 4 Fracture morphology image of BN-Al-ZrB2-TiC composite material prepared in Example 2; from Figure 4 It can be seen that the binder is combined with the cBN particles and is dense, and there are no defects such as pores in the sintered body. When the sample is fractured, there is transgranular fracture and intergranular fracture, but transgranular fracture is dominant.

[0079] Figure 5 Bending strength curve of BN-Al-ZrB2-TiC composite material prepared in Example 3, tested by three-point bending method, loading speed is 0.5mm / min. from Figure 5 It can be seen that the bending strength increases first and then decreases with the gradual increase of the cBN content in the sintered body; when the cBN content increases to a certain extent, the binder content in the sintered body is low, and the cBN particles are mostly mechanically bonded, thereby causing the performance of the sintered body to decrease.

[0080] Figure 6 Vickers hardness curve of BN-Al-ZrB2-TiC composite material prepared in Example 3, tested by indentation method, loading load is 5kN, and pressure holding time is 15s. from Figure 6 It can be seen that the Vickers hardness increases with the gradual increase of the cBN content in the sintered body. This is because the hardness of the sintered body is mainly determined by cBN, and the cBN particles gradually increase, so the hardness also gradually increases.

[0081] The above only describes the preferred embodiments of the present application, and it should be noted that for ordinary skilled in the art, without departing from the principles of the present application, a number of improvements and refinements can be made, and these improvements and refinements should also be considered as the protection scope of the present application.

Claims

1. A method for preparing a BN-Al-ZrB2-TiC composite material, characterized in that, Includes the following steps: Zirconium boride and titanium carbide are first mixed to obtain a first mixture. The first mixture is then mixed with cubic boron nitride, aluminum powder and solvent in a second mixture, and then ball-milled, dried and sieved in sequence to obtain the second mixture. The second mixture was subjected to segmented pressure sintering to obtain a BN-Al-ZrB2-TiC composite material; The molar ratio of zirconium boride to titanium carbide is 1:0.6~1.4; The mass ratio of cubic boron nitride, aluminum powder and the first mixture is 50~80:6:14~44; The segmented pressure sintering is carried out using a six-sided top press; the pressure applied by the six-sided top press is 4~7 GPa. The segmented pressure sintering includes: a first stage: a temperature of 900~1400℃, a holding time of 1~3min, and a heating rate of 300~500℃ / min from room temperature to the temperature of the first stage; and a second stage: a temperature of 1500~2000℃, a holding time of 5~10min, and a heating rate of 300~500℃ / min from the temperature of the first stage to the temperature of the second stage.

2. The preparation method according to claim 1, characterized in that, The first mixing time is 15~45 min.

3. The preparation method according to claim 1, characterized in that, The ball mill operates at a speed of 80-200 r / min for 360-840 min, with a ball-to-material ratio of 2-5:

1.

4. The preparation method according to claim 1, characterized in that, The drying temperature is 60~100℃ and the time is 16~30h; the mesh size of the sieve used for sieving is 100~400 mesh.

5. The BN-Al-ZrB2-TiC composite material prepared by the preparation method according to any one of claims 1 to 4.

6. The application of the BN-Al-ZrB2-TiC composite material of claim 5 in PcBN cutting tools.

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