阅读说明：本技术 一种镍铬增强氧化铝复合材料制备方法 (Preparation method of nickel-chromium-reinforced aluminum oxide composite material ) 是由 黄剑 苏美娟 张倩 汪力 苏碧云 王文珍 于 2019-12-17 设计创作，主要内容包括：本发明公开了一种镍铬增强氧化铝复合材料制备方法,称取镍铬合金粉,氧化铝粉,钇稳定氧化锆加入到球磨罐中,加入球磨珠混合；将混合后的粉末进行球磨处理,球磨完成后用筛网将料球分离,将分离的粉料加入聚乙烯醇,均匀混合后过筛,放置阴凉处陈腐,然后压制成型；将压制成型的坯体放在阴凉处静置,再将坯体放入烘箱内经三次升温和保温处理后取出；将烘干坯体置于马弗炉中排胶,然后放入真空炉中加热,随后随炉冷,制成镍铬增强氧化铝复合材料。本发明有效提高氧化铝陶瓷的强度,解决使用过程中易碎,脆性断裂等缺陷。(The invention discloses a preparation method of a nickel-chromium-reinforced alumina composite material, which comprises the steps of weighing nickel-chromium alloy powder, alumina powder and yttrium-stabilized zirconia, adding into a ball milling tank, adding ball milling beads and mixing; performing ball milling treatment on the mixed powder, separating material balls by using a screen after the ball milling is finished, adding polyvinyl alcohol into the separated powder, uniformly mixing, sieving, placing in a shade for ageing, and then pressing and forming; placing the pressed and formed blank in a shade place for standing, placing the blank into an oven, and taking out after three times of heating and heat preservation; and placing the dried blank body in a muffle furnace for rubber discharge, then placing the blank body in a vacuum furnace for heating, and then cooling the blank body along with the furnace to prepare the nickel-chromium reinforced aluminum oxide composite material. The invention effectively improves the strength of the alumina ceramic and solves the defects of frangibility, brittle fracture and the like in the use process.)

1. A preparation method of a nickel-chromium reinforced alumina composite material is characterized by comprising the following steps:

s1, weighing 30-50 parts of nichrome powder, 30-70 parts of alumina powder and 1-10 parts of yttrium-stabilized zirconia, adding into a ball milling tank, adding 50-100 parts of ball milling beads, and mixing;

s2, performing ball milling treatment on the mixed powder, separating material balls by using a screen after the ball milling is finished, adding 10-15 parts of polyvinyl alcohol into the separated powder, uniformly mixing, sieving, standing in a shade place for aging, and then pressing and molding;

s3, placing the pressed and formed blank in a shade place for standing, placing the blank into an oven, and taking out after three times of heating and heat preservation;

and S4, placing the dried blank body obtained in the step S3 in a muffle furnace for glue discharging, then placing in a vacuum furnace for heating, and then cooling along with the furnace to obtain the nickel-chromium reinforced aluminum oxide composite material.

2. The method for preparing the nickel-chromium-reinforced aluminum oxide composite material according to claim 1, wherein in step S1, the particle size of the nickel-chromium alloy powder is 5-30 um, and the particle size of the aluminum oxide powder is 1-20 um.

3. The preparation method of the nickel-chromium-reinforced aluminum oxide composite material as claimed in claim 1, wherein in step S2, the ball milling treatment time is 10-20 h, a screen mesh with 20-40 meshes is adopted for sieving, the mixture is uniformly mixed and sieved by a screen mesh with 10-40 meshes, the ageing time is 10-20 h, and the pressure for press forming is 10-100 MPa.

4. The preparation method of the nickel-chromium-reinforced aluminum oxide composite material as claimed in claim 1, wherein in the step S3, the standing time is 20-40 h.

5. The preparation method of the nickel-chromium-reinforced aluminum oxide composite material according to claim 1, wherein in the step S3, the temperature is raised for the first time at 30-50 ℃ and the heat preservation time is 5-20 hours, the temperature is raised for the second time at 50-70 ℃ and the heat preservation time is 5-20 hours, and the temperature is raised for the third time at 70-100 ℃ and the heat preservation time is 10-30 hours.

6. The preparation method of the nickel-chromium-reinforced aluminum oxide composite material according to claim 1, wherein in the step S4, in the rubber removal treatment in the muffle furnace, the temperature rise rate is controlled to be 1-3 ℃/min, the temperature is raised to 500-600 ℃, and the temperature is maintained for 3-5 hours.

7. The preparation method of the nickel-chromium-reinforced aluminum oxide composite material according to claim 1, wherein in step S4, nitrogen is filled in a vacuum furnace, the vacuum degree is controlled to be 5-10 Pa, and the nickel-chromium-reinforced aluminum oxide composite material is cooled along with the furnace after two temperature raising treatments.

8. The preparation method of the nickel-chromium-reinforced aluminum oxide composite material according to claim 7, wherein the temperature rise rate of the first temperature rise is 4-8 ℃/min, the temperature rise is 1000-1100 ℃, the heat preservation time is 1-30 min, the temperature rise rate of the second temperature rise is 1-5 ℃/min, the temperature rise is 1200-1300 ℃, and the heat preservation time is 1-5 h.

Technical Field

The invention belongs to the technical field of composite material preparation, and particularly relates to a preparation method of a nickel-chromium-reinforced aluminum oxide composite material.

Background

The alumina ceramic has the advantages of high mechanical strength, good wear resistance, corrosion resistance, good insulating property, low dielectric loss under high frequency, rich raw material, low price and the like, so that the alumina ceramic becomes an advanced ceramic material with the largest current production and the widest application range, and the prior alumina ceramic is mainly prepared by adopting a sintering process. The alumina is an ionic bond compound, the particle diffusion coefficient is very low, the melting point is high, the sintering temperature of pure alumina can reach the compact degree generally at a high temperature of more than 1800 ℃, which brings great difficulty to the improvement of the performance of alumina ceramics, the high-efficiency low-energy-consumption preparation of the alumina ceramics is commonly used hot-pressing sintering, ultrahigh-pressure sintering and hot isostatic pressing sintering, but the sintered ceramics have poor toughness and limit the application range.

Disclosure of Invention

The technical problem to be solved by the invention is to provide a preparation method of a nickel-chromium-enhanced alumina composite material aiming at the defects in the prior art, the preparation method is simple and convenient, the prepared nickel-chromium-alumina ceramic composite material has the double properties of metal and ceramic, the sintering temperature is reduced, the problem of high energy consumption caused by the traditional sintering is reduced, and the requirement of customers on the service performance is met.

The invention adopts the following technical scheme:

a preparation method of a nickel-chromium reinforced alumina composite material comprises the following steps:

s1, weighing 30-50 parts of nichrome powder, 30-70 parts of alumina powder and 1-10 parts of yttrium-stabilized zirconia, adding into a ball milling tank, adding 50-100 parts of ball milling beads, and mixing;

s2, performing ball milling treatment on the mixed powder, separating material balls by using a screen after the ball milling is finished, adding 10-15 parts of polyvinyl alcohol into the separated powder, uniformly mixing, sieving, standing in a shade place for aging, and then pressing and molding;

s3, placing the pressed and formed blank in a shade place for standing, placing the blank in an oven, heating for three times, keeping the temperature, and taking out;

and S4, placing the dried blank body obtained in the step S3 in a muffle furnace for glue discharging, then placing in a vacuum furnace for heating, and then cooling along with the furnace to obtain the nickel-chromium reinforced aluminum oxide composite material.

Specifically, in step S1, the particle size of the nichrome powder is 5 to 30um, and the particle size of the alumina powder is 1 to 20 um.

Specifically, in the step S2, the ball milling treatment time is 10-20 hours, a 20-40 mesh screen is adopted for sieving, the mixture is uniformly mixed and then sieved by a 10-40 mesh screen, the ageing time is 10-20 hours, and the pressure of the compression molding is 10-100 MPa.

Specifically, in the step S3, the standing time is 20-40 h.

Specifically, in step S3, the temperature is raised to 30-50 ℃ for the first time, the heat preservation time is 5-20 hours, the temperature is raised to 50-70 ℃ for the second time, the heat preservation time is 5-20 hours, the temperature is raised to 70-100 ℃ for the third time, and the heat preservation time is 10-30 hours.

Specifically, in the step S4, in the glue discharging treatment in the muffle furnace, the temperature rising rate is controlled to be 1-3 ℃/min, the temperature is raised to be 500-600 ℃, and the temperature is kept for 3-5 h.

Specifically, in step S4, nitrogen gas is filled into the vacuum furnace, the vacuum degree is controlled to be 5-10 Pa, and the furnace is cooled after two temperature raising treatments.

Further, the temperature rise rate of the first temperature rise is 4-8 ℃/min, the temperature rise temperature is 1000-1100 ℃, the heat preservation time is 1-30 min, the temperature rise rate of the second temperature rise is 1-5 ℃/min, the temperature rise is 1200-1300 ℃, and the heat preservation time is 1-5 h.

Compared with the prior art, the invention has at least the following beneficial effects:

the invention relates to a preparation method of a nickel-chromium-reinforced alumina composite material, which adopts alumina powder and nickel-chromium alloy powder, adds a small amount of yttrium-stabilized zirconia powder, ball-mills and mixes the materials, and sinters the materials into the nickel-chromium-reinforced alumina composite material under the protection of nitrogen through dry pressing forming, thereby improving the strength of alumina ceramic and solving the defects of frangibility, brittle fracture and the like in the using process.

Further, the smaller particle size reduces the sintering temperature and increases the material strength.

Furthermore, the material is aged to obtain the maximum viscosity, so that the material does not crack after being dry-pressed.

Furthermore, the temperature is raised for three times, so that the moisture is slowly discharged out of the green body and is not cracked.

Furthermore, the temperature rise due to glue discharge can avoid polluting the furnace chamber.

Furthermore, the heating body is protected quickly by the primary temperature rise, the electric energy is saved, and the ceramic is contracted slowly and compactly by the secondary slow temperature rise, so that cracks are not generated.

In conclusion, the invention effectively improves the strength of the alumina ceramic and solves the defects of frangibility, brittle fracture and the like in the use process.

The technical solution of the present invention is further described in detail by the following examples.

Detailed Description

The invention relates to a preparation method of a nickel-chromium reinforced alumina composite material, which comprises the following steps:

s1, weighing 30-50 parts of 5-30 um nickel-chromium alloy powder, weighing 30-70 parts of 1-20 um alumina powder, weighing 1-10 parts of yttrium stabilized zirconia, adding into a ball milling tank, and weighing 50-100 parts of ball milling beads, and adding into the ball milling tank.

S2, placing the nodular graphite tank on a ball mill, performing ball milling for 10-20 hours, separating the material balls by using a screen after the ball milling is finished, adding 10-15 parts of polyvinyl alcohol into the separated powder, uniformly mixing, screening by using a screen with 10-40 meshes, placing the powder in a shade place for ageing for 10-20 hours, and pressing under the pressure of 10-100 MPa to prepare the molded product

S3, placing the pressed and formed blank in a shade place for standing for 20-40 h, then placing the blank in an oven, adjusting the temperature to 30-50 ℃, preserving the heat for 5-20 h, heating to 50-70 ℃, preserving the heat for 5-20 h, and finally heating to 70-100 ℃ and preserving the heat for 10-30 h. Taking out after drying

S4, placing the dried blank in a muffle furnace, heating to 500-600 ℃, keeping the temperature for 3-5 h, heating at the rate of 1-3 ℃/min, completing glue discharging, then placing the discharged glue blank in a vacuum furnace, vacuumizing to 5-10 Pa, starting heating after nitrogen protection is filled, heating at the rate of 4-8 ℃/min for the first time, the temperature of 1000-1100 ℃, keeping the temperature for 1-30 min, heating at the rate of 1-5 ℃/min for the second time, heating to 1200-1300 ℃, keeping the temperature for 1-5 h, and then cooling with the furnace to prepare the nickel-chromium reinforced aluminum oxide composite material.