粉末注射成形制备薄壁Al_(2)O_(3)-B_(4)C环形芯块

Preparation of Al_(2)O_(3)-B_(4)C thin-wall tube pellet by powder injection molding

使用多组元蜡基粘结剂,通过粉末注射成形工艺,结合溶剂脱脂和热脱脂,成功烧结制备出壁厚为0.7 mm的近净尺寸环形Al_(2)O_(3)-B_(4)C薄壁管。结果表明,当石蜡占粘结剂质量分数45%时,喂料具有较低的黏度和较好的抗弯强度;当固相体积分数为58%时,喂料在保证低黏度的前提下具有良好性能。当烧结温度在1550℃至1650℃范围内时,芯块相对密度及抗弯强度随温度上升而增高;当烧结温度达到1650℃时,芯块的密度及强度有所下降,芯块密度随B_(4)C粒度增大而增大,抗弯强度随粒度增大先增大后减小。

The annular Al_(2)O_(3)-B_(4)C thin wall tube with the wall thickness of near 0.7 mm was successfully sintered by powder injection molding combined with the solvent degreasing and thermal degreasing,using the multi-component wax-based binder.The results show that,when the paraffin mass fraction is 45%,the feedstock has the lower viscosity and the better bending strength.When the solid phase volume fraction is 58%,the feedstock has the good performance in the premise of low viscosity.When the sintering temperature is in the range of 1550℃ to 1650℃,the relative density and the bending strength of the pellets increase with the increase of temperature.When the sintering temperature reaches 1650℃,the density and strength of the pellets begin to decrease slightly,the density increases with the increase of the B_(4)C particle size,and the bending strength increases first and then decreases with the increase of particle size.