A process for preparing ceramic particle-reinforced steel matrix composites

Abstract

This invention discloses a process for preparing ceramic particle-reinforced steel-based composite materials, belonging to the field of wear-resistant material preparation technology. The method of this invention includes: a powder mixing process, a powder injection molding process, a vacuum debinding process, and a vacuum hot-pressing sintering process. The process scheme is as follows: First, ceramic particles with attached rare earth elements Y and La, iron powder, and an organic binder are added to a ball mill jar and thoroughly mixed using a planetary ball mill. The granulated powder is heated and plasticized, then injected into a mold cavity using a powder injection molding machine. After curing and shaping through processes such as pressure holding, debinding is performed using a vacuum debinding furnace. Finally, the ceramic particle-reinforced steel-based composite material is obtained through vacuum hot-pressing sintering. The method of this invention can prepare metal-based composite materials on a large scale, resulting in a denser microstructure and wear-resistant materials with better resistance to wear, corrosion, and impact.

Description

TECHNICAL FIELD

[0001] The present application relates to a process for preparing a ceramic particle reinforced steel matrix composite material, and belongs to the technical field of wear-resistant material preparation. BACKGROUND

[0002] Friction and wear has become the most important failure mode of mechanical parts. According to statistics, about 30% of the world's primary energy is consumed annually due to friction and wear, and material wear caused by friction also causes about 60% of mechanical parts to fail. Reducing material wear by adding ceramic particles to make steel matrix composites has become an important measure to increase the reliability of mechanical equipment, prolong the service life of equipment, and save raw materials and energy. With the rapid development of industry, the demand for precision and efficiency in the manufacturing field and mechanical equipment is increasingly urgent.

[0003] Invention patent CN104209498B introduces a method for preparing an interface modification layer of a ceramic particle reinforced metal matrix composite material, which improves the bonding strength of the ceramic particle and the metal interface. Invention patent CN101112718B proposes a ceramic particle reinforced iron matrix composite material and its preparation method. The ceramic particle reinforced iron matrix composite material prepared has a ceramic particle area percentage of 15% to 45% on the working surface, a ceramic particle hardness of ≥66HRC, and a composite layer containing ceramic particles with a thickness of 1mm to 15mm. The wear resistance of the prepared composite material is more than 5 times that of its matrix material, and the invention is suitable for preparing thick and large wear-resistant composite castings. Invention patent CN109382492B introduces a method and device for continuously preparing a particle reinforced metal matrix composite material. The method uses the upper continuous casting process to stably add ceramic particle powder to the metal liquid through a feeding device, so that the ceramic particles are uniformly distributed in the metal matrix with a certain viscosity. After rapid solidification and molding, a particle reinforced metal matrix composite material with uniform ceramic particle distribution and continuous production is prepared, which refines the grain size of the base material. However, it is not suitable for large-scale continuous actual production. Invention patent CN113106313A introduces a rare earth doped WC particle reinforced steel matrix composite material and its preparation method. The preparation process only dopes one kind of rare earth, and the preparation method is the conventional tabletting method.

[0004] The traditional preparation method uses single rare earth doping, while the present application uses double rare earth doping. Compared with single rare earth doping, the co-doping of rare earth elements Y and La can accelerate the mutual diffusion of Fe, C and W elements in the composite material, thereby promoting the formation of the interface reaction zone of the composite material in advance and increasing the width of the interface reaction zone. The doping of rare earth Y increases the content of the interface phase (Fe3W3C) of the composite material, and the hardness of the interface reaction phase of the composite material increases after the doping of rare earth elements Y and La, and the Young's modulus decreases, making the thermal shock resistance of the composite material better than that of the composite material without the addition of rare earth.

[0005] Traditional processes for preparing ceramic particle-reinforced steel matrix composites involve preparing the reinforcing phase into a preform, then combining it with a metal matrix to obtain the desired composite material. The traditional methods for preparing the reinforcing phase include powder mixing, tableting, molding, and vacuum sintering. However, the preparation of preforms from reinforcing ceramic particles sometimes requires composite materials with complex shapes, which cannot be processed using traditional methods. Powder injection molding technology from the machining industry is introduced to produce composite materials, offering high efficiency and the ability to mold complex structural components. In traditional tableting, friction between the mold wall and the powder, as well as between powder particles, results in highly uneven pressure distribution, leading to uneven microstructure in the pressed blank. This causes uneven shrinkage during sintering, necessitating a reduction in sintering temperature to mitigate this effect. Consequently, the product exhibits high porosity, poor material density, and low density, severely impacting its mechanical properties. In contrast, injection molding is a fluid forming process. In injection molding, molten granules uniformly fill the mold cavity, forming a relatively consistent pressure at all points within the cavity, eliminating the unavoidable density gradient problem along the pressing direction inherent in traditional powder metallurgy pressing. To a certain extent, it overcomes the uneven density, microstructure, and properties inherent in traditional powder metallurgy. The presence of a binder ensures uniform powder distribution, thereby eliminating microstructure inhomogeneities in the blank and allowing the density of sintered products to reach the theoretical density of the material. Typically, pressed products can only achieve a maximum density of 85% of the theoretical density. The high density of powder injection molded products increases strength, toughness, ductility, electrical and thermal conductivity, and magnetic properties. It is highly efficient and easily enables mass production. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides a process for preparing ceramic particle-reinforced steel matrix composites. The method includes rare earth doping, powder mixing, injection molding, and vacuum sintering. Specifically, the method includes the following steps:

[0007] (1) Place ceramic particles and paraffin particles in a container, place the container in water for water bath heating, and stir to slowly melt the paraffin particles and attach them to the surface of the ceramic particles. After cooling, place them in a grinding bowl for grinding.

[0008] (2) Place the mixture of rare earth Y and La with the ceramic particles ground in step (1) into a ball mill jar, pour in anhydrous ethanol until the mixed powder is submerged, and ball mill to obtain ceramic particles coated with rare earth elements Y and La.

[0009] (3) The ceramic particles coated with rare earth elements Y and La obtained in step (2) are mixed with steel powder and organic binder in a ball mill.

[0010] (4) Powder injection molding: the powder mixed in step (3) is granulated and then added to the injection molding machine in a plasticized state to feed into the mold cavity and solidify to obtain a green body.

[0011] (5) Vacuum sintering: the molded green body is degreased using a vacuum degreasing furnace, then sintered using a vacuum hot pressing sintering furnace, and finally oil quenched after sintering to obtain a dense ceramic particle reinforced steel matrix composite material.

[0012] Preferably, the chemical composition of the steel powder and its mass percentage are as follows: C: 0.4% to 0.6%, Si: 0.1% to 0.25%, Mn: 20% to 24%, Cr: 3% to 4%, Ti: 0.06% to 0.095%, V: 0.44% to 0.65%, Mo: 0.2% to 0.4%, N: 0.2% to 0.3%, P < 0.01%, S < 0.01%, and the rest is Fe and unavoidable impurities. The increase of elements Mn and Cr in the alloy effectively improves the mechanical properties of the ceramic particle reinforced steel matrix composite material.

[0013] Preferably, in step (1), the ceramic particles are WC; the mass fraction of ceramic particles added is 96% to 99% of the total mass of ceramic particles and paraffin, and the mass fraction of paraffin added is 1% to 4% of the total mass of ceramic particles and paraffin; the water bath heating temperature is 60 to 70°C.

[0014] Preferably, in step (2), the amount of rare earth Y and La mixture added is 1% to 4% of the sum of the mass of ceramic particles and graphite, and the ratio of rare earth elements is Y: La = 1: 1.

[0015] Preferably, in step (2), the ball milling conditions are as follows: 300g of grinding balls are added for every 100g of powder, then the ball mill tank is evacuated and filled with argon, and the cycle is repeated three times to prevent WC particles in the ball mill tank from being oxidized during ball milling. The ball mill tank is placed in a planetary ball mill and ball milled at a speed of 300 to 400 r / min for 8 to 9h.

[0016] Preferably, in step (3), the steel powder particle size is 80 to 100 mesh, the mass of the ceramic particles coated with rare earth elements Y and La added is (2:3) to (1:1) of the mass of the steel powder; the organic binder is composed of paraffin, microcrystalline paraffin, and water-soluble methyl ethyl ketone binder, and the addition mass ratio is paraffin: microcrystalline paraffin: methyl ethyl ketone = (6 to 7): (1 to 2): (0.5 to 1); the mass ratio of powder to binder is 15:1 to 20:1, the ball milling speed is 400 to 600 revolutions per minute, and the ball milling time is 5 to 8h.

[0017] Preferably, in step (4), the mixed powder is heated to 150-200 DEG C by screw stirring in an injection molding machine, the plasticized mixture is injected into a mold cavity through the injection molding machine feeding system, and pressure is maintained to compensate for cooling shrinkage, with a pressure of 40-50 MPa and a pressure maintaining time of 1-3 min. When solidified, the part has sufficient strength, the mold is opened, and the part is ejected with a ejector pin to obtain a green body.

[0018] Preferably, in step (5), the debinding temperature is 100-150 DEG C, the vacuum degree is 0.4-0.6 MPa, the debinding time is 4-5 h, the sintering temperature is 900-920 DEG C, the pressure is 40-50 MPa, the vacuum degree is 0.6-0.8 MPa, the holding time is 30-60 min, and the oil quenching uses mineral oil.

[0019] A process principle for preparing the ceramic particle reinforced steel matrix composite material is as follows:

[0020] By coating the ceramic particles with rare earth doping, a metallurgical reaction between the ceramic particles and the matrix can occur during sintering, the mutual diffusion of the elements Fe, C and W of the composite material can be accelerated by jointly doping the coating with rare earth elements Y and La, so that the interface reaction zone of the composite material is formed in advance and the width of the interface reaction zone is increased, the content of the interface phase (Fe3W3C) of the composite material is increased by doping with rare earth Y, the hardness of the interface reaction phase of the composite material is increased and the Young's modulus is reduced after doping with rare earth elements Y and La, the thermal shock resistance of the composite material is better than that of the composite material without adding rare earth, the rare earth is beneficial to widening the interface phase, so that the strength and toughness of the composite material are further improved. The metal powder injection molding technology can be used to mass-produce the metal matrix composite material. In injection molding, the molten particles uniformly fill the mold cavity, the pressure at each point in the mold cavity is basically consistent, and the density gradient problem along the pressing direction in traditional powder metallurgy pressing forming is eliminated. In hot-pressing sintering, pressure and temperature are applied during sintering, and the pressure is maintained for a certain time. The pressure in sintering makes the composite material structure more dense, to a certain extent, the density, structure and performance of the traditional powder metallurgy are not uniform, the interface bonding force is improved, and the ceramic particle reinforced steel matrix composite material with high density, uniform distribution of reinforced ceramic particles and high interface bonding strength is obtained.

[0021] The beneficial effects of the present application are:

[0022] (1) Compared with single rare earth doping, the hardness of the interface reaction phase of the composite material is increased and the Young's modulus is reduced after doping with rare earth elements Y and La, so that the thermal shock resistance of the composite material is better than that of the composite material with single rare earth doping.

[0023] (2) The present application adopts the ceramic reinforced particle steel matrix composite material, which has good wear resistance, corrosion resistance, high temperature resistance, impact resistance and other abilities of wear-resistant materials.

[0024] (3) In the process of preparing ceramic particle steel matrix composite material, sometimes the composite material with complex shape cannot be processed by traditional scheme, and the metal powder injection molding technology introduced from the metal processing industry is used to prepare the composite material, which has high efficiency and can form complex structure. The method can mass-produce metal matrix composite material, obtain material with good density, and has good wear resistance, corrosion resistance, high temperature, impact and other abilities of wear-resistant material. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 is a microstructure diagram of ceramic particle reinforced steel matrix composite material;

[0026] Figure 2 is the wear curve of ceramic particle reinforced steel matrix composite material. DETAILED DESCRIPTION

[0027] The invention will be further described in detail below in combination with the drawings and specific examples, but the protection scope of the invention is not limited to the contents described.

[0028] Example 1

[0029] A process for preparing a ceramic particle reinforced steel matrix composite material, comprising the following steps:

[0030] (1) Put 98 grams of ceramic particles WC and 2 grams of paraffin particles in a container, heat the container in a water bath at 70℃, and stir to slowly melt the paraffin particles and adhere to the surface of the ceramic particles. After cooling to 50℃, place in a grinding bowl and grind to a particle diameter of 50μm.

[0031] (2) Put 1 gram of rare earth Y and 1 gram of rare earth La mixture and the ceramic particles ground in step (1) into a ball mill jar, pour anhydrous ethanol until the mixed powder is immersed, 102g of powder is matched with 306g of grinding balls, then the ball mill jar is vacuumed and filled with argon, and the cycle is repeated three times to prevent WC particles in the ball mill jar from being oxidized during ball milling. Put the ball mill jar into a planetary ball mill and ball mill the powder at a speed of 300r / min for 9h (working time) to obtain ceramic particles coated with rare earth elements Y and La.

[0032] (3) Take 40 grams of ceramic particles coated with rare earth elements Y and La obtained in step (2) and 60 grams of 80 steel powder, add 6 grams of organic binder paraffin, 1 gram of microcrystalline paraffin and 1 gram of methyl ethyl ketone to obtain a water-soluble binder, and mix the powder and the binder in a mass ratio of 15:1 in a ball mill. The ball mill speed is 600r / min and the ball milling time is 5h.

[0033] (4) Powder injection molding: the powder treated in step (3) is heated to 200°C in an injection molding machine by screw stirring, and the plasticized mixture is injected into the mold cavity through the injection machine feeding system, with a pressure of 40 MPa for 1 min to compensate for the shrinkage during cooling. After cooling and solidification, the mold is opened and the part is ejected with a ejector pin to obtain a green body.

[0034] (5) Vacuum sintering: the formed green body is removed from the organic binder using a vacuum debinding furnace, with a debinding temperature of 100°C, a vacuum degree of 0.6 MPa, and a debinding time of 4h. Then, vacuum hot-press sintering furnace is used for sintering treatment, with a sintering temperature of 900°C, a pressure of 40 MPa, a vacuum degree of 0.6 MPa, and a holding time of 60 min. Then, mineral oil quenching is used to obtain a dense ceramic particle reinforced steel matrix composite material.

[0035] Example 2

[0036] A process for preparing a ceramic particle reinforced steel matrix composite material, comprising the following steps:

[0037] (1) Place 99 grams of ceramic particles WC and 1 gram of paraffin particles in a container, place the container in a water bath at 70°C for water bath heating, and stir to slowly melt the paraffin particles and adhere to the surface of the ceramic particles. After cooling to 60°C, place in a grinding bowl and grind to a particle diameter of 60μm.

[0038] (2) Mix 0.5 grams of rare earth Y and 0.5 grams of rare earth La with the ceramic particles ground in step (1) and place them in a ball mill jar. Pour in anhydrous ethanol until the mixed powder is immersed, 101g of powder is mixed with 300g of grinding balls. Then, the ball mill jar is evacuated and filled with argon, and the process is repeated three times to prevent the WC particles in the ball mill jar from being oxidized during the ball milling process. The ball mill jar is placed in a planetary ball mill at a speed of 400r / min for 8h (working time) to obtain ceramic particles coated with rare earth elements Y and La.

[0039] (3) Take 50 grams of ceramic particles coated with rare earth elements Y and La obtained in step (2) and 50 grams of 100 steel powder, add 7 grams of organic binder paraffin, 2 grams of microcrystalline paraffin, and 0.5 grams of methyl ethyl ketone to obtain a water-soluble binder. The mass ratio of powder to binder is 20:1. Mix the powder in a ball mill at a speed of 400r / min for 8h.

[0040] (4) Powder injection molding: the powder mixed in step (3) is heated to 200℃ by screw stirring in an injection molding machine, and the plasticized mixture is injected into the mold cavity through the injection machine feeding system, the pressure is 50 MPa for 3 min to compensate for the shrinkage during cooling. When cooled and solidified, the mold is opened, the part is ejected with a ejector pin, and a green body is obtained.

[0041] (5) Vacuum sintering: the formed green body is removed from the organic binder using a vacuum debinding furnace, the debinding temperature is 150℃, the vacuum degree is 0.4MPa, and the debinding time is 5h. Then, the vacuum hot-pressing sintering furnace is used for sintering treatment, the sintering temperature is 920℃, the pressure is 40MPa, the vacuum degree is 0.8MPa, and the holding time is 30min. Then, the mineral oil quenching is carried out to obtain a dense ceramic particle reinforced steel matrix composite material.

[0042] Example 3

[0043] A process for preparing a ceramic particle reinforced steel matrix composite material, comprising the following steps:

[0044] (1) Put 96 grams of ceramic particles WC and 4 grams of paraffin particles in a container, place the container in a 70℃ water bath for heating, and stir to slowly melt the paraffin particles and adhere to the surface of the ceramic particles. After cooling to 40℃, grind in a grinding bowl to a particle diameter of 60μm.

[0045] (2) Put the mixture of 2 grams of rare earth Y and 2 grams of rare earth La with the ground ceramic particles in step (1) into a ball mill tank, pour anhydrous ethanol until the mixed powder is immersed, and every 104g of powder is matched with 312g of grinding balls. Then, the ball mill tank is vacuumed and filled with argon, and the cycle is repeated three times to prevent the WC particles in the ball mill tank from being oxidized during the ball milling process. Put the ball mill tank into a planetary ball mill and ball mill for 9h (working time) at a speed of 300r / min to obtain ceramic particles coated with rare earth elements Y and La.

[0046] (3) Take 40 grams of ceramic particles coated with rare earth elements Y and La obtained in step (2) and 60 grams of 45 steel powder, add 6 grams of organic binder paraffin, 1 gram of microcrystalline paraffin, and 0.5 gram of methyl ethyl ketone to obtain a water-soluble binder, and mix the powder and the binder in a mass ratio of 15:1. Mix the powder in a ball mill at a speed of 500r / min for 5h.

[0047] (4) Powder injection molding: the powder mixed in step (3) is heated to 150℃ by screw stirring in an injection molding machine, and the plasticized mixture is injected into the mold cavity through the injection machine feeding system, the pressure is 40 MPa for 3 min to compensate for the shrinkage during cooling. When cooled and solidified, the mold is opened, the part is ejected with a ejector pin, and a green body is obtained.

[0048] (5) Vacuum sintering: the green part after molding is removed from the organic binder by vacuum debinding furnace, the debinding temperature is 100°C, the vacuum degree is 0.5 MPa, and the holding time is 4 h. Then, the vacuum hot-pressing sintering furnace is used for sintering treatment, the sintering temperature is 900°C, the pressure is 50 MPa, the vacuum degree is 0.7 MPa, and the holding time is 30 min. Then, the mineral oil is used for oil quenching to obtain a dense ceramic particle reinforced steel matrix composite.

[0049] Comparative Example 1

[0050] A process for preparing a ceramic particle reinforced steel matrix composite includes the following steps:

[0051] (1) 40 grams of 40% ceramic particles and 60 grams of 60% 45 steel powder are added to a ball mill, then 6 grams of 60% organic binder paraffin, 1 gram of 10% microcrystalline paraffin, and 0.5 gram of 5% methyl ethyl ketone water-soluble binder are added. The mass ratio of powder to binder is 15:1. The powder is mixed in the ball mill for 5 h.

[0052] (2) The mixed powder is heated to 200°C by screw stirring in an injection molding machine. The plasticized mixture is injected into the mold cavity through the injection machine feeding system, and the pressure is 40 MPa for 3 min to compensate for the cooling shrinkage. After cooling and solidification, the mold is opened, the part is ejected with a ejector pin, and a green part is obtained.

[0053] (3) The molded green part is removed from the organic binder by vacuum debinding furnace, the debinding temperature is 100°C, the time is 4 h, then the vacuum hot-pressing sintering furnace is used for sintering treatment, the sintering temperature is 900°C, the pressure is 40 MPa, the holding time is 60 min, and then the mineral oil is used for oil quenching to obtain a dense ceramic particle reinforced steel matrix composite.

[0054] Comparative Example 2

[0055] A process for preparing a ceramic particle reinforced steel matrix composite includes the following steps:

[0056] (1) 99 grams of ceramic particles WC and 1 gram of paraffin particles are placed in a container, the container is placed in a 70°C water bath for heating, and the paraffin particles are slowly melted and attached to the surface of the ceramic particles by stirring. After cooling to 50°C, it is placed in a grinding bowl and ground to a particle diameter of 60 μm.

[0057] (2) Put 1 gram of rare earth Y and the ceramic particles after grinding in step (1) into a ball mill tank, pour in anhydrous ethanol until the mixed powder is immersed, add 300 g of grinding balls for every 100 g of powder, then vacuumize the ball mill tank while filling it with argon, circulate three times to prevent the WC particles in the ball mill tank from being oxidized during the ball milling process, and put the ball mill tank into a planetary ball mill to ball mill the powder for 9 h (working time) at a speed of 300 r / min to obtain ceramic particles coated with rare earth elements Y and La.

[0058] (3) Weigh 40 grams of rare earth Ya coated ceramic particles obtained in step (2) and 60 grams of 60% 45 steel powder into a ball mill, then add 7 grams of 70% organic binder paraffin, 1 gram of 10% microcrystalline paraffin, and 0.5 gram of 5% methyl ethyl ketone water-soluble binder, with a powder to binder mass ratio of 20:1, and mix the powder in the ball mill for 5 h.

[0059] (4) Use the mixed powder to heat to 200°C by screw stirring in an injection molding machine, inject the plasticized mixture into the mold cavity through the injection machine feeding system, and pressurize for 3 min at a pressure of 40 MPa to compensate for cooling shrinkage. When the cooling solidification is sufficient, open the mold, use a ejector pin to eject the part, and obtain a green body.

[0060] (5) Use a vacuum debinding furnace to remove the organic binder after molding the blank, with a debinding temperature of 100°C and a time of 4 h, then use a vacuum hot pressing sintering furnace for sintering treatment, with a sintering temperature of 920°C, a pressure of 40 MPa, and a holding time of 60 min, and then use mineral oil for oil quenching to obtain a dense ceramic particle reinforced steel matrix composite material.

[0061] Comparative Example 3

[0062] A process for preparing a ceramic particle reinforced steel matrix composite material, comprising the following steps:

[0063] (1) Put 99 grams of ceramic particles WC and 1 gram of paraffin particles into a container, place the container in a 70°C water bath for heating, and stir to slowly melt the paraffin particles and adhere them to the surface of the ceramic particles. After cooling to 60°C, grind in a mortar to a particle diameter of 60 μm.

[0064] (2) Put 1 gram of rare earth La and the ceramic particles after grinding in step (1) into a ball mill tank, pour in anhydrous ethanol until the mixed powder is immersed, then vacuumize the ball mill tank while filling it with argon, circulate three times to prevent the WC particles in the ball mill tank from being oxidized during the ball milling process, and put the ball mill tank into a planetary ball mill to ball mill the powder for 9 h (working time) at a speed of 300 r / min to obtain ceramic particles coated with rare earth elements Y and La.

[0065] (3) Take 40 grams of rare earth element Ya coated ceramic particles obtained in step (2) and 60 grams of 60% 45 steel powder into a ball mill, then add 6 grams of 60% organic binder paraffin, 2 grams of 20% microcrystalline paraffin, and 1 gram of 1% methyl ethyl ketone water-soluble binder, the mass ratio of powder to binder is 15:1, mix the powder in the ball mill, and the ball milling time is 8h.

[0066] (4) The mixed powder is heated to 150°C by screw stirring in an injection molding machine, the plasticized mixture is injected into the mold cavity through the injection machine feeding system, the pressure is 40 MPa and the pressure holding time is 3 min to compensate for the cooling shrinkage. After cooling and solidification, when the part has sufficient strength, the mold is opened and the part is ejected with a ejector pin to obtain a green body.

[0067] (5) The molded green body is removed from the organic binder using a vacuum debinding furnace at a debinding temperature of 100°C for 4h, and then sintered using a vacuum hot pressing sintering furnace at a sintering temperature of 900°C, a pressure of 50 MPa, and a holding time of 30 min, and then oil quenched with mineral oil to obtain a dense ceramic particle reinforced steel matrix composite material.

[0068] The ceramic particle reinforced steel matrix composite material prepared in the examples was subjected to performance testing:

[0069] (1) The ceramic particle reinforced steel matrix composite material prepared in the examples was subjected to microhardness testing using a digital Vickers microhardness tester, the test force used was 0.98N, the load time was 10s, 10 random areas were measured, and the average hardness value was taken, the results are shown in Table 1.

[0070] (2) The ceramic particle reinforced steel matrix composite material prepared in the examples was subjected to wear resistance test, the coating was subjected to friction and wear test using a reciprocating friction and wear tester, the friction pair was a steel ball with a diameter of 6mm, the load was 50N, the friction rate was 3mm / s, the sliding length was 3mm, and the sliding time was 60min; the results are shown in Table 1.

[0071] The ceramic particle reinforced steel matrix composite material prepared was subjected to compression test, the compression strength and strain of the prepared composite material are shown in Table 1.

[0072] Table 1 Mechanical and wear properties of ceramic particle reinforced steel matrix composite materials prepared in Examples 1-3 and Comparative Examples 1-3

[0073]

[0074] According to the ceramic particle reinforced steel matrix composite material performance data in Table 1, the strength, hardness and the like of Examples 1-3 are higher than those of Comparative Examples 1-3, and the rare earth doping can greatly improve the bonding strength. It can be known that the comprehensive mechanical properties of Examples 1-3 are excellent. Examples 1-3 are ceramic particle reinforced steel matrix composites with different contents of two kinds of rare earth elements, and Comparative Examples 1-3 are ceramic particle reinforced steel matrix composites without rare earth elements and with one kind of rare earth element, and the performance has great difference; the wear performance of Comparative Example 1 and Example 1 has obvious difference, and the main reason is that Comparative Example 1 does not add rare earth elements, so the mechanical properties of Comparative Example 1 are lower than those of Example 1, mainly because the bonding strength of the ceramic particles and the matrix without the effect of rare earth elements is poor, the wear performance is not good, and the hardness and strength are lower than those of Example 1; Examples 1, 2 and 3 use different contents of two kinds of rare earth elements, which has certain influence on the bonding strength and wear performance of the composite material, and it is found that the performance of the sample with 1% Y and 1% La is better than that of the sample with 0.5% and 2%, so reasonable adjustment of the content ratio of the rare earth elements is beneficial to the improvement of the performance of the composite material.

[0075] Finally, it should be noted that the above examples are only used to illustrate the technical solutions of the present application, and are not intended to limit the scope of protection of the present application. Although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application can be modified or replaced by equivalents without departing from the essence and scope of the technical solutions of the present application.

Claims

1. A process for the production of a ceramic particle reinforced steel matrix composite material, characterized in that, Specifically comprising the following steps: (1) Put the ceramic particles and paraffin particles in a container, place the container in water for water bath heating, and stir to slowly melt the paraffin particles and adhere to the surface of the ceramic particles, and then cool and grind in a grinding bowl; (2) Put the mixture of rare earth Y and La and the ground ceramic particles in step (1) into a ball mill tank, pour anhydrous ethanol until the mixed powder is immersed, and ball mill to obtain ceramic particles coated with rare earth elements Y and La; (3) Mix the ceramic particles coated with rare earth elements Y and La obtained in step (2) with steel powder and organic binder in a ball mill; (4) Powder injection molding: After granulating the mixed powder obtained in step (3), it is added to the injection molding machine in a heated plasticized state, fed into the mold cavity, and solidified and molded to obtain a green body; (5) Vacuum sintering: The molded green body is degreased by a vacuum degreasing furnace to remove the organic binder, and then sintered by a vacuum hot pressing sintering furnace, and finally the sintered composite material is oil quenched to obtain a dense ceramic particle reinforced steel matrix composite material; The chemical composition and mass percentage of the steel powder are C: 0.4%~0.6%, Si: 0.1%~0.25%, Mn: 20%~24%, Cr: 3%~4%, Ti: 0.06%~0.095%, V: 0.44%~0.65%, Mo: 0.2%~0.4%, N: 0.2%~0.3%, P < 0.01%, S < 0.01%, and the rest is Fe and unavoidable impurities; In step (2), the amount of rare earth Y and La mixture added is 1~4% of the sum of the mass of ceramic particles and paraffin, and the mass ratio of rare earth elements is Y:La =1:1; In step (3), the steel powder particle size is 80~100 mesh, the mass of the rare earth element Y and La coated ceramic particles is 2:3~1:1 of the mass of the steel powder; the organic binder is composed of paraffin, microcrystalline paraffin and methyl ethyl ketone water-soluble binder, and the mass ratio is paraffin: microcrystalline paraffin: methyl ethyl ketone = (6~7): (1~2): (0.5~1); the mass ratio of powder to organic binder is 15:1~20:1, the ball milling speed is 400~600 rpm, and the ball milling time is 5~8h; In step (4), the mixed powder is heated to 150~200℃ by screw stirring in the injection molding machine, the plasticized mixture is injected into the mold cavity through the injection molding machine feeding system, and the pressure is 40~50MPa to compensate for the shrinkage during cooling, and the pressure holding time is 1~3min. When solidified, the mold is opened, the part is ejected with a ejector pin, and a green body is obtained; In step (5), the degreasing temperature is 100~150℃, the vacuum degree is 0.4MPa~0.6MPa, and the degreasing time is 4~5h; the sintering temperature is 900~920℃, the pressure is 40~50MPa, the vacuum degree is 0.6MPa~0.8MPa, and the holding time is 30~60min; the oil quenching uses mineral oil.

2. The process for the preparation of ceramic particle reinforced steel matrix composite material as claimed in claim 1 wherein: The ceramic particles in step (1) are WC; the mass fraction of the ceramic particles is 96-99% of the total mass of the ceramic particles and the paraffin, and the mass fraction of the paraffin is 1-4% of the total mass of the ceramic particles and the paraffin; the temperature of the water bath heating is 60-70 DEG C.

3. The process for the preparation of ceramic particle reinforced steel matrix composite material as claimed in claim 1 wherein: In step (2), the ball milling conditions are as follows: 300 g of grinding balls are added for every 100 g of powder, then the ball milling tank is vacuumized and filled with argon, and the circulation is repeated for three times to prevent the WC particles in the ball milling tank from being oxidized during the ball milling, and the ball milling tank is placed in a planetary ball mill and ball-milled at a rotating speed of 300-400 r / min for 8-9 h.

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