CN101100382A - Manufacture method for Ti3AlC2 processable ceramics material - Google Patents

Abstract

A kind of preparation method of _Ti3AlC2 machinable ceramic material, at first, fully mix Ti powder, Al powder and C powder; Add sodium stearate dispersant in _the mixture, adopt dry method ball milling, form main crystal phase to be Ti - Al intermetallic compound, TiC and small composite powder containing titanium and aluminum; the composite powder obtained by ball milling is dried in vacuum; the dried powder is put into a graphite grinding tool, and hot-pressed under argon or vacuum conditions Just sinter. The invention utilizes Ti powder, Al powder, C powder and a small amount of additives to react in situ to form intermediate phases such as TiC and Ti-Al after high-energy ball milling. The composite powder is hot-pressed and sintered to synthesize a machinable ceramic material with a single crystal phase of Ti ₃ AlC ₂ . Due to the simple process, low firing temperature, low pressure, uniform and compact structure, and low cost.

Description

A kind of preparation method of Ti3AlC2 machinable ceramic material

technical field

The invention belongs to the field of ceramic material manufacture _, and in particular relates to a preparation method of _Ti3AlC2 machinable ceramic material.

Background technique

Ti ₃ AlC ₂ is a new machinable ceramic material with unique properties. The performance of this material combines the advantages of metal materials and ceramic materials, such as good electrical and thermal conductivity, relatively low hardness, plasticity at high temperatures, and the possibility of processing with high-speed tools or wire cutting. Processability, also has comprehensive properties such as high elastic modulus, low density, high thermal stability and good oxidation resistance of ceramics, and has broad application prospects in the fields of high-temperature structural components, chemical anti-corrosion materials, electrode materials and machinable materials. .

At present, there are two main preparation methods of this material, in-situ hot pressing sintering and hot isostatic pressing sintering. These two methods use Ti-Al-C or TiC-Al-Ti as raw materials to directly prepare titanium-aluminum-carbon Ti ₃ AlC ₂ bulk materials by reaction sintering. The reaction synthesis temperature is high (above 1400°C), the hot pressing pressure is high (about 35MPa), the purity is difficult to control, and there are many impurities, including reactant residues and intermediate products (TiC, Ti-Al intermetallic compounds, etc.), There are also Ti ₂ AlC and Ti ₃ AlC phases, which affect the performance of the material. Therefore, how to take an effective way to synthesize high-purity Ti ₃ AlC ₂ materials will be the development direction of this material in the future.

Contents of the invention

The object of the present _invention is to overcome the deficiencies of the prior art and provide a method for preparing _Ti3AlC2 machinable ceramic material with simple preparation process, low temperature, low hot pressing pressure and low manufacturing cost. The material prepared by the method has the characteristics of high purity, low impurity content, fine and dense crystal grains, and good comprehensive mechanical properties.

In order to achieve the above object, the technical solution adopted in the present invention is: first, fully mix 67.56-71.11% Ti powder, 20.00-28.00% Al powder and 4.44-8.89% C powder by mass percentage; 0.2-0.5% sodium stearate dispersant, adopt dry ball milling, the rotating speed of the ball mill is 800-1000 revolutions per minute, the mass ratio of material and ball is 1:10, ball milling for 10-12 hours, the main crystal phase is Ti - Al intermetallic compound, TiC and fine composite powder containing a small amount of titanium and aluminum; the composite powder obtained by ball milling is vacuum-dried at 70-80°C for 4-5 hours; the dried powder is put into a graphite grinding tool , under argon or vacuum conditions at 1200 ° C -1300 ° C, 5-15 MPa pressure hot pressing sintering 0.5-1 hour.

The invention utilizes Ti powder, Al powder, C powder and a small amount of additives to react in situ to form intermediate phases such as TiC and Ti-Al after high-energy ball milling. The composite powder is hot-pressed and sintered to synthesize a machinable ceramic material with a single crystal phase of Ti ₃ AlC ₂ . Due to the simple process, low firing temperature, low pressure, uniform and compact structure, and low cost.

Description of drawings

Figure 1 shows the XRD analysis results of the high-energy ball milling process of Ti powder, Al powder, and C powder. The main crystal phases are TiC, TiAl ₃ and a small amount of unreacted titanium and aluminum. The abscissa is the diffraction angle, and the ordinate is the diffraction peak intensity. ;

Figure 2 shows the XRD analysis results of the sintered sample at 1300°C, where the abscissa is the diffraction angle, and the ordinate is the diffraction peak intensity;

Fig. 3 is the SEM analysis result of Ti ₃ AlC ₂ synthesized at 1300°C.

Detailed ways

The present invention will be described in further detail below in conjunction with the accompanying drawings and embodiments.

Embodiment 1, referring to Fig. 1-3, at first, 67.56% Ti powder, 28% Al powder and 4.44% C powder are fully mixed by mass percentage; Add the sodium stearate dispersant of mixture quality 0.4% in the mixture , using dry ball milling, the speed of the ball mill is 900 revolutions per minute, the mass ratio of material and ball is 1:10, and the ball mill is 10 hours, the main crystal phase is Ti-Al intermetallic compound, TiC and contains a small amount of titanium and aluminum. Composite powder; the composite powder obtained by ball milling was vacuum-dried at 80°C for 4 hours; the dried powder was put into a graphite grinding tool, and sintered by hot pressing at 1300°C and 5MPa under argon or vacuum conditions for 0.5 hours. It can be seen from Figure 2 that the material is a single crystal phase Ti ₃ AlC ₂ ; it can be seen from Figure 3 that the structure of the material is dense and uniform. It has a microcrystalline lamellar structure.

Embodiment 2, at first, fully mix 71.11% Ti powder, 20% Al powder and 8.89% C powder by mass percentage; Add the sodium stearate dispersant of mixture quality 0.2% in the mixture, adopt dry ball milling, The speed of the ball mill is 800 rpm, the mass ratio of material and ball is 1:10, and the ball mill is 11 hours to form a fine composite powder whose main crystal phase is Ti-Al intermetallic compound, TiC and contains a small amount of titanium and aluminum; the ball mill The obtained composite powder was vacuum-dried at 75°C for 4.2 hours; the dried powder was put into a graphite grinding tool, and hot-pressed and sintered at 1200°C and 12MPa pressure for 1 hour under argon or vacuum conditions.

Embodiment 3, at first, 70% Ti powder, 25% Al powder and 5% C powder are fully mixed by mass percentage; Add the sodium stearate dispersant of mixture quality 0.5% in the mixture, adopt dry ball milling, The rotation speed of the ball mill is 1000 rpm, the mass ratio of material and ball is 1:10, and the ball mill is 12 hours to form a fine composite powder whose main crystal phase is Ti-Al intermetallic compound, TiC and contains a small amount of titanium and aluminum; the ball mill The obtained composite powder was vacuum-dried at 72°C for 4.5 hours; the dried powder was put into a graphite grinding tool, and hot-pressed and sintered at 1270°C and 8 MPa pressure for 0.6 hour under argon or vacuum conditions.

Embodiment 4, at first, 68% Ti powder, 24% Al powder and 8% C powder are fully mixed by mass percentage; Add the sodium stearate dispersant of mixture quality 0.3% in the mixture, adopt dry ball milling, The rotating speed of the ball mill is 850 revolutions per minute, the mass ratio of material and ball is 1:10, and the ball milling time is 10.5 hours to form a fine composite powder whose main crystal phase is Ti-Al intermetallic compound, TiC and contains a small amount of titanium and aluminum; The composite powder obtained by ball milling was vacuum-dried at 77°C for 4.8 hours; the dried powder was put into a graphite grinding tool, and hot-pressed and sintered at 1250°C and 10MPa pressure for 0.7 hours under argon or vacuum conditions.

Embodiment 5, at first, fully mix 71% Ti powder, 22% Al powder and 7% C powder by mass percentage; Add the sodium stearate dispersant of mixture quality 0.2% in the mixture, adopt dry ball milling, The rotating speed of the ball mill is 950 rpm, the mass ratio of material and ball is 1:10, and the ball milling takes 11.5 hours to form a fine composite powder whose main crystal phase is Ti-Al intermetallic compound, TiC and contains a small amount of titanium and aluminum; The obtained composite powder was vacuum-dried at 70°C for 5 hours; the dried powder was put into a graphite grinding tool, and hot-pressed at 1230°C under argon or vacuum conditions at a pressure of 5, 12, 8, 10, and 15 MPa Sinter for 0.9 hours.

Claims (6)

1. A preparation method of _{Ti3AlC2 machinable} ceramic material, characterized in that: 1) First, fully mix 67.56-71.11% of Ti powder, 20.00-28.00% of Al powder and 4.44-8.89% of C powder by mass percentage; 2) Add sodium stearate dispersant of 0.2-0.5% of the mass of the mixture into the mixture, adopt dry ball milling, the rotating speed of the ball mill is 800-1000 revolutions per minute, the mass ratio of material to ball is 1: 10, and the ball mill is 10-12 Hours, the main crystal phase is Ti-Al intermetallic compound, TiC and contains a small amount of titanium, aluminum fine composite powder; 3) Vacuum-dry the composite powder obtained by ball milling at 70-80°C for 4-5 hours; 4) Put the dried powder into a graphite grinding tool, heat press and sinter at 1200°C-1300°C and 5-15MPa pressure for 0.5-1 hour under argon or vacuum conditions. 2. The method for preparing _Ti3AlC2 machinable ceramic material according to claim 1, characterized in that: firstly, fully mix 67.56% Ti powder, 28% Al _powder and 4.44% C powder according to mass percentage; Add the sodium stearate dispersant of mixture quality 0.4% in the mixture, adopt dry method ball milling, the rotating speed of ball mill is 900 revs per minute, material, ball mass ratio is 1: 10, ball milling 10 hours, form main crystal phase and be Ti -Al intermetallic compound, TiC and fine composite powder containing a small amount of titanium and aluminum; the composite powder obtained by ball milling was dried in vacuum at 80°C for 4 hours; Or hot-press sintering at 1300°C and 5MPa pressure for 0.5 hours under vacuum conditions. 3. The method for preparing _Ti3AlC2 machinable ceramic material according to claim 1, characterized in that: firstly, fully mix 71.11% Ti powder, 20% Al _powder and 8.89% C powder according to mass percentage; Add the sodium stearate dispersant of mixture quality 0.2% in the mixture, adopt dry method ball milling, the rotating speed of ball mill is 800 revs per minute, material, ball mass ratio is 1: 10, ball milling 11 hours, form main crystal phase and be Ti - Al intermetallic compound, TiC and fine composite powder containing a small amount of titanium and aluminum; the composite powder obtained by ball milling was dried in vacuum at 75°C for 4.2 hours; Or hot pressing and sintering at 1200°C and 12MPa pressure for 1 hour under vacuum condition. 4. The method for preparing _Ti3AlC2 machinable ceramic material according to claim 1, characterized in that: firstly, fully mix 70% Ti powder, 25% Al powder and 5% C _powder according to mass percentage; Add the sodium stearate dispersant of mixture quality 0.5% in the mixture, adopt dry method ball milling, the rotating speed of ball mill is 1000 revs per minute, material, ball mass ratio is 1: 10, ball milling 12 hours, form main crystal phase and be Ti -Al intermetallic compound, TiC and fine composite powder containing a small amount of titanium and aluminum; the composite powder obtained by ball milling was vacuum-dried at 72°C for 4.5 hours; Or hot pressing and sintering at 1270°C and 8MPa pressure for 0.6 hours under vacuum conditions. 5. The method for preparing _Ti3AlC2 machinable ceramic material according to claim 1, characterized in that: firstly, fully mix 68% Ti powder, 24% Al powder and 8% C _powder according to mass percentage; Add the sodium stearate dispersant of mixture quality 0.3% in the mixture, adopt dry method ball milling, the rotating speed of ball mill is 850 revs per minute, material, ball mass ratio are 1: 10, ball milling 10.5, hour, form main crystal phase as Fine composite powders of Ti-Al intermetallic compound, TiC and containing a small amount of titanium and aluminum; the composite powder obtained by ball milling was vacuum-dried at 77°C for 4.8 hours; Hot pressing and sintering at 1250°C and 10MPa pressure for 0.7 hours under air or vacuum conditions. 6. The method for preparing _Ti3AlC2 machinable ceramic material according to claim 1, characterized in that: firstly, fully mix 71% Ti powder, 22% Al powder and 7% C _powder according to mass percentage; Add the sodium stearate dispersant of mixture quality 0.2% in the mixture, adopt dry ball milling, the rotating speed of ball mill is 950 revs per minute, material, ball mass ratio is 1: 10, ball milling 11.5 hours, form main crystal phase and be Ti - Al intermetallic compound, TiC and fine composite powder containing a small amount of titanium and aluminum; the composite powder obtained by ball milling was vacuum-dried at 70°C for 5 hours; Or hot pressing and sintering at 1230° C. under vacuum conditions and pressures of 5, 12, 8, 10, and 15 MPa for 0.9 hours.

Images