CN103341613B - Preparation method of prefabricated body of ceramic-metal composite wear-resistant part - Google Patents

Abstract

The invention discloses a kind of preparation method of precast body of ceramet composite wear-resistant part, it is characterized in that: complete in accordance with the following steps: (1), by ceramic grain surface nickel plating, the thickness of described nickel coating is 10-200um, and described ceramic particle is particle diameter is 0.5-3.0mm; (2) solid paraffin and oleic acid heating, is got, after melted paraffin wax, add ceramic particle and self-fluxing alloy powder wherein, then be fully uniformly mixed at 60-100 DEG C and obtain mixed material, mixing time is greater than 2h, and wherein, the quality of atoleine is the 10%-30% of ceramic particle quality, the quality of described oleic acid is the 3%-5% of Quality of Paraffin Waxes, and the quality of self-fluxing alloy powder is the 15%-50% of ceramic particle quality.(3), the material mixed is added extrusion molding in plunger type extrusion shaping machine and obtain preform blank; (4), preform blank is imbedded alumina powder jointed in, put into draft glue discharging furnace binder removal, discharge the organic matter in base substrate, then sintering obtains precast body, and the temperature of sintering is lower than the melt temperature of self-fluxing alloy.<pb pnum="1" />

Description

Preparation method of prefabricated body of ceramic-metal composite wear-resistant part

technical field

The invention relates to the technical field of wear-resistant composite materials, in particular to a method for preparing a prefabricated body of ceramic particle-reinforced metal composite wear-resistant parts.

Background technique

Abrasion is the most basic type of failure of prefabricated parts, and it is commonly found in many industries such as metallurgy, mining, thermal power, machinery, cement, and coal mines. This has caused a great waste of raw materials and a huge consumption of energy. According to incomplete statistics, my country consumes more than 5 million tons of metal wear-resistant materials every year. It can be seen that improving the wear resistance of mechanical equipment and parts can effectively reduce energy consumption and increase labor productivity.

In response to the above situation, it was proposed to make composite materials from metal and ceramics. Ceramic-metal composite materials are a new type of composite materials that combine the high wear resistance and high hardness of ceramics with the toughness of metal materials. The metal-ceramic composite materials used in my country are mainly imported from abroad. Compared with imported products, the performance of the metal-ceramic composite materials produced in my country still has a certain gap at this stage. Regardless of domestic or foreign metal-ceramic composite materials, the main process principle is to rely on ceramic particles to reinforce metal materials.

At present, the most studied is to use alumina, silicon carbide, and tungsten carbide ceramic particles as aggregates, alloy powder or matrix self-fluxing alloy powder as filler, select a suitable binder, etc., and press molding to make prefabricated blanks. , and then dried and sintered to obtain a preform.

Contents of the invention

In order to solve the above technical problems, the purpose of the present invention is to provide a continuous production, high efficiency and stability, the green body has a large number of pores, which can make the matrix metal liquid penetrate better, the ceramic particles are wrapped more uniformly, and can be obtained by casting. The invention relates to a method for preparing a prefabricated body of a ceramic particle reinforced metal composite wear-resistant material with higher strength and wear resistance of a composite wear-resistant part.

The object of the present invention is achieved in the following way: a method for preparing a prefabricated body of a ceramic-metal composite wear-resistant part, characterized in that: it is completed according to the following steps:

(1), the surface of the ceramic particles is nickel-plated, the thickness of the nickel-plated layer is 10-200um, and the particle size of the ceramic particles is 0.5-3.0mm;

(2) Take solid paraffin and oleic acid and heat it. After the paraffin is melted, add ceramic particles and self-fluxing alloy powder to it, and then fully stir and mix at 60-100°C to obtain a mixed material. The stirring time is greater than 2h, wherein, The mass of the liquid paraffin is 10%-30% of the mass of the ceramic particles, the mass of the oleic acid is 3%-5% of the mass of the paraffin wax, and the mass of the self-fluxing alloy powder is 10%-50% of the mass of the ceramic particles %.

(3), adding the mixed material into a plunger extrusion molding machine and extruding to obtain a prefabricated body;

(4) Embedding the prefabricated green body in the alumina powder body, putting it into a debinding furnace to remove the glue, discharging the organic matter in the green body, taking out the green body, and then sintering to obtain the prefabricated body.

With the above technical scheme, the fluidity of ceramic particles meets the needs of extrusion through the addition of paraffin and oleic acid, which overcomes the fact that the prefabricated parts of ceramic particles reinforced metal wear-resistant materials can only be formed by pressing because of the large particle size of ceramic particles. , can not realize the defect of extruding molding with an extruder, realize continuous production, and the production efficiency is high, fast and stable. The prepared prefabricated body obtains a certain strength by solidification of organic matter such as paraffin wax. After the degumming treatment, the organic matter is discharged. The green body has a large number of pores, which can make the matrix metal liquid penetrate better, and the ceramic particles are wrapped more uniformly. The obtained composite wear-resistant parts have higher strength and wear resistance. The ceramic particles are treated with nickel plating, and self-fluxing alloy powder is added at the same time, so that the bonding strength between the ceramic particles and between the ceramic particles and the matrix metal liquid is good enough. It can also reduce the thermal shock to the ceramic material itself when casting the base metal liquid, and prevent bursting.

In the above technical solution: the self-fluxing alloy powder is aluminum-nickel alloy powder or aluminum-copper alloy powder or aluminum-silicon alloy powder.

In the above technical scheme: the ceramic particles are a mixture of three kinds of ceramic particles whose particle diameters are respectively 0.5-1.0mm, 1.0-2.0mm, and 2.0-3.0mm, and their mass ratio is 2-3:4-6: 2-3. The gradation of ceramic particles in three different size ranges is adopted. After mixing large particles and small particles, the ceramic particles are more evenly distributed, better combined, better dense, and improve fluidity, which is not only convenient for molding, but also improves prefabrication. The impact resistance and wear resistance of parts.

In the above-mentioned technical scheme: in step (2), also add the plasticizer stearic acid of 0%-5% or the plasticizer dibutyl phthalate of 0%-5% or 0%-5% plasticizer tributyl phosphate.

In the above technical scheme: the extrusion pressure in step (3) is 3-20Mpa. Extrusion pressure is low.

In the above technical solution: the degumming temperature is 200-500° C., and the temperature is kept constant for 20-30 hours, subject to the elimination of all organic matter.

In the above technical solution: the sintering temperature is 650-1100° C., and the sintering time is 4-5 hours.

In the above technical solution: the ceramic particles are at least one of silicon carbide, tungsten carbide, titanium carbide, silicon nitride, zirconium oxide, aluminum oxide, and ZTA ceramic particles.

Beneficial effects: the present invention aims at making ceramic preforms conveniently and efficiently by using a new molding technology. The preform is prepared by thermoplastic extrusion molding technology, which has high production efficiency and can realize continuous production. The prepared prefabricated body obtains a certain strength by the solidification of paraffin and other organic matter. After the organic matter is removed through large-scale drying and debinding equipment, the green body has a large number of pores, which can better infiltrate the matrix liquid metal. The ceramic particles are pre-plated with nickel, so that the ceramic particles and the metal substrate have sufficient bonding strength. The ceramic preform prepared by the method has good compactness and stable performance.

Detailed ways

The present invention will be further described below in conjunction with specific embodiment:

Implementation Example 1

1. The zirconia ceramic particles with a particle size of 0.5-1.0mm, 1.0-2.0mm, and 2.0-3.0mm are plated with a layer of metal nickel with a thickness of about 10um on the surface by electroless nickel plating, and then according to the particle size, they are respectively The mass ratio of 0.5-1.0mm, 1.0-2.0mm, 2.0-3.0mm zirconia ceramic particles is 2:6:2. Weigh the ceramic particles and mix them evenly. The process of nickel plating includes the processes of surface treatment and plating.

Surface preparation consists of the following 5 steps:

(1) Degreasing: soak in anhydrous alcohol solution for 10-35 minutes, wash with deionized water under the action of ultrasonic waves, completely degrease the surface of ceramic particles, and then dry naturally.

(2) Roughening: Under the action of ultrasonic waves, soak in hydrofluoric acid at room temperature to roughen the surface of ceramic particles.

(3), sensitization: soak for 4-6min at room temperature with a sensitization solution containing stannous chloride dihydrate and hydrochloric acid under ultrasonic waves.

(4) Activation: Under ultrasonic waves, a solution containing palladium chloride and hydrochloric acid is used to activate the surface of the ceramic particles.

(5) Reduction: Under ultrasonic waves, use sodium hypophosphite solution to reduce the residual Pd ²⁺ on the surface of ceramic particles, soak at room temperature for 3-5 minutes, then wash with deionized water and dry naturally.

Put the surface-treated ceramic particles into the nickel plating solution, under constant stirring, adjust the pH value to 4.0-5.0 with acetic acid/sodium acetate buffer solution, at a temperature of 80-90°C, and apply plating for 1-1.5h. The components can be nickel sulfate 20-30g/L, sodium hypophosphite 20-30g/L, lactic acid 7-9m L/L, ammonium molybdate 10-35mg L.

2. Add solid paraffin and oleic acid respectively on a mixer with a heating device, the amount of paraffin added is 10% of the mass of the ceramsite particles, and the amount of oleic acid added is 5% of the mass of paraffin wax. After the paraffin wax is melted, add ceramic particles and self-fluxing alloy powder, aluminum-nickel alloy powder. The mass of self-fluxing alloy powder is 15% of the mass of ceramic particles, and then stir and mix evenly at 60°C. The mixing time must not be less than 2 hours.

3. Pour the mixed material into a plunger extruder, and extrude it with an extrusion pressure of 3-20Mpa. After the organic matter is cooled and solidified, it is demolded to obtain a prefabricated body.

4. Embed the prepared body into alumina powder, put it into a vacuum debinding furnace, and keep the temperature at 500°C for 20 hours until all organic matter is removed. After the organic matter is removed, the green body is taken out, and then sintered at 700°C for 5 hours. Cooling out of the oven to obtain a preform.

Implementation example 2

1. Nickel-plating the alumina ceramic particles whose particle size is respectively 0.5-1.0mm, 1.0-2.0mm, and 2.0-3.0mm according to the method in Example 1, the thickness of the nickel-plated layer is about 200um, and then by mass ratio 3: 4: Weigh the ceramic particles of the above three particle sizes in a ratio of 3 and mix them evenly.

2. Add solid paraffin and oleic acid respectively on a mixer with a heating device, the amount of paraffin added is 30% of the mass of the ceramsite particles, and the amount of oleic acid added is 3% of the mass of paraffin wax. After the paraffin is melted, add ceramic particles and self-fluxing alloy powder, aluminum-copper alloy powder. The mass of the self-fluxing alloy powder is 50% of the mass of the ceramic particles, and then stir and mix evenly at a temperature of 60-100°C. The mixing time must not be less than 2 hours.

3. Pour the mixed clinker into the plunger extruder, and extrude it with an extrusion pressure of 3-20Mpa. After the organic matter is cooled and solidified, it is demoulded to obtain a prefabricated body.

4. Embed the prepared body into alumina powder, put it into a vacuum debinding furnace, and keep the temperature at 200°C for 30 hours until all organic matter is removed. After the organic matter is removed, the green body is taken out, and then sintered at 650°C for 4 hours. Cooling out of the oven to obtain a preform.

Implementation example 3

1. ZTA ceramic particles (zirconia accounts for 30%) with a particle size of 0.5-1.0 mm, 1.0-2.0 mm, and 2.0-3.0 mm. According to the mode of embodiment 1, on the surface, plate the metal nickel that one deck thickness is about 50um, be the ZTA ceramic grain mass ratio 3: 5: 2 of 0.5-1.0mm, 1.0-2.0mm, 2.0-3.0mm by particle size then Proportionally weigh the ceramic particles and mix them evenly.

2. Add solid paraffin and oleic acid respectively on a mixer with a heating device, the amount of paraffin added is 20% of the mass of the ceramsite particles, and the amount of oleic acid added is 4% of the mass of paraffin wax. After the paraffin wax is melted, the heated ceramic particles and the self-fluxing alloy powder, aluminum-silicon alloy powder are added, and the mass of the self-fluxing alloy powder is 25% of the mass of the ceramic particles. Then stir and mix evenly at a temperature of 60-100°C, and the mixing time must not be less than 2 hours.

3. Pour the mixed material into a plunger extruder, and extrude it with an extrusion pressure of 3-20Mpa. After the organic matter is cooled and solidified, it is demolded to obtain a prefabricated body.

4. Embed the prepared body into alumina powder, put it into a vacuum debinding furnace, and keep the temperature at 450°C for 25 hours until all organic matter is removed. After the organic matter is removed, the green body is taken out, and then sintered at 720°C for 4.5 hours. Cooling out of the oven to obtain a preform.

Implementation Example 4

1. Alumina ceramic particles and tungsten carbide ceramic particles with a particle size of 0.5-1.0mm, 1.0-2.0mm, and 2.0-3.0mm. The ratio of the total mass of the tungsten carbide ceramic particles to the total mass of the alumina ceramic particles is 1:1. Plating a layer of metallic nickel with a thickness of about 60um on the surface according to the method of Example 1, then the mass ratio of alumina ceramic particles with a particle size of 0.5-1.0mm, 1.0-2.0mm, and 2.0-3.0mm is 2: 5: 3 Weigh the ceramic particles according to the ratio of 0.5-1.0mm, 1.0-2.0mm, 2.0-3.0mm tungsten carbide ceramic particles with a mass ratio of 2:5:3 and mix them evenly.

2. Add solid paraffin and oleic acid respectively on a mixer with a heating device, the amount of paraffin added is 20% of the mass of the ceramsite particles, and the amount of oleic acid added is 4% of the mass of paraffin wax. After the paraffin wax is melted, the heated ceramic particles and the self-fluxing alloy powder, aluminum-silicon alloy powder are added, and the mass of the self-fluxing alloy powder is 25% of the mass of the ceramic particles. Then stir and mix evenly at a temperature of 60-100°C, and the mixing time must not be less than 2 hours.

3. Pour the mixed material into a plunger extruder, and extrude it with an extrusion pressure of 3-20Mpa. After the organic matter is cooled and solidified, it is demolded to obtain a prefabricated body.

4. Embed the prepared body into alumina powder, put it into a vacuum debinding furnace, and keep the temperature at 450°C for 25 hours until all organic matter is removed. After the organic matter is removed, the green body is taken out, and then sintered at 720°C for 4.5 hours. Cooling out of the oven to obtain a preform.

The other steps of Implementation Example 5 are the same as those of Example 1, except that 0.5% stearic acid based on the mass of the ceramic particles is added in Step 2.

The other steps of Example 6 are the same as those of Example 2, except that 0.2% of the mass of ceramic particles of dibutyl phthalate is added in Step 2.

Embodiment 7-9 other steps are respectively identical with embodiment 1, and difference is that the add-on of paraffin is respectively 9%, 8%, 5% of ceramic granule quality, and the amount of oleic acid is respectively 3%, 2% of paraffin amount. %, 1%, as a result their extrusion pressure is far greater than 20Mpa, embodiment 7 can be extruded substantially, embodiment 8 and 9 can not be well realized and extruded from the extruder.

Embodiment 10-12, other steps are identical with embodiment 1, and difference is, the add-on of paraffin is respectively 32%, 40%, 50% of ceramic granule quality, and the amount of oleic acid is respectively 3%, 5% of paraffin amount. %, 1%, as a result, Examples 10 and 11 were taken out after debinding, and the bonding between ceramic particles and ceramic particles was poor, the bonding was not good, the compactness was poor, and cracking occurred when casting the matrix molten metal. The preform obtained in Example 12 cracked when casting the matrix molten metal.

The present invention is not limited to the specific examples, and the examples are only a further description of the present invention. The ceramic particles of the present invention can be made of silicon carbide, tungsten carbide, titanium carbide, silicon nitride, zirconia, aluminum oxide, ZTA ceramic particles Either or a combination. The self-fluxing alloy powder can be any one of aluminum-nickel alloy powder, aluminum-copper alloy powder or aluminum-silicon alloy powder, or it can be a self-fluxing alloy powder with a melting temperature within 650-1100°C that is not listed in the present invention can be. In a word, any improvement made on the gist of the present invention falls within the protection scope of the present invention.

Claims (8)

1. a preparation method for the precast body of ceramet composite wear-resistant part, is characterized in that: complete in accordance with the following steps:

(1), by ceramic grain surface nickel plating, the thickness of described nickel coating is 10-200 μm, and described ceramic particle particle diameter is 0.5-3.0mm;

(2) solid paraffin and oleic acid heating, is got, after melted paraffin wax, add ceramic particle and self-fluxing alloy powder wherein, then be fully uniformly mixed at 60-100 DEG C and obtain mixed material, mixing time is greater than 2h, and wherein, the quality of described solid paraffin is the 10%-30% of ceramic particle quality, the quality of described oleic acid is the 3%-5% of Quality of Paraffin Waxes, and the quality of described self-fluxing alloy powder is the 10%-50% of ceramic particle quality;

(3), the material mixed is added extrusion molding in plunger type extrusion shaping machine and obtain preform blank;

(4), preform blank is imbedded alumina powder jointed in, put into draft glue discharging furnace binder removal, discharge the organic matter in base substrate, take out base substrate, then sintering obtains precast body.

2. the preparation method of the precast body of ceramet composite wear-resistant part according to claim 1, is characterized in that: described self-fluxing alloy powder is alumel powder or aluminium copper powder or alusil alloy powder.

3. the preparation method of the precast body of ceramet composite wear-resistant part according to claim 1, it is characterized in that: described ceramic particle is respectively the mixture of three kinds of ceramic particles of 0.5-1.0mm, 1.0-2.0mm, 2.0-3.0mm by particle diameter, their mass ratio is 2-3:4-6:2-3.

4. the preparation method of the precast body of ceramet composite wear-resistant part according to any one of claim 1-3, it is characterized in that: in step (2), be also added with the plasticizer stearic acid that is less than ceramic particle quality 5% or be less than the plasticizer phthalic acid dibutyl ester of ceramic particle quality 5% or be less than the plasticizer tributyl phosphate of ceramic particle quality 5%.

5. the preparation method of the precast body of ceramet composite wear-resistant part according to any one of claim 1-3, is characterized in that: in step (3), extrusion pressure is 3-20MPa.

6. the preparation method of the precast body of ceramet composite wear-resistant part according to any one of claim 1-3, is characterized in that: described dump temperature is 200-500 DEG C, constant temperature 20-30 hour, all gets rid of be as the criterion with organic matter.

7. the preparation method of the precast body of ceramet composite wear-resistant part according to any one of claim 1-3, is characterized in that: described sintering temperature is 650-1100 DEG C, sintering time 4-5 hour.

8. the preparation method of the precast body of ceramet composite wear-resistant part according to any one of claim 1-3, is characterized in that: described ceramic particle is at least one in carborundum, tungsten carbide, titanium carbide, silicon nitride, zirconia, aluminium oxide, ZTA ceramic particle.