ZrO2/Cu复合材料内氧化制备工艺

采用非真空熔炼和高压水雾化法制得Cu-0.6%Zr(质量分数)合金粉末,经粒径分选后进行低温氧化、N₂+5%H₂(体积分数)混合气体还原和真空等离子放电烧结(SPS)成型,制备得到ZrO₂/Cu原位增强复合材料。结果表明: 对合金粉末低温氧化处理时,温度过低,氧化速度慢,温度过高,易发生过氧化和粉末结块现象,最佳氧化参数为230℃×1 h; N₂+5%H₂气体流量控制在200 mL/min条件下,通过烧氢实验确定最佳还原参数为250℃×1 h; 在30 MPa压力条件下,经850℃×2 h 真空放电等离子烧结(SPS),ZrO₂/Cu试样的导电率>83% IACS(international annealed copper standard),硬度>HB 75,软化温度为900℃。

Preparation of ZrO2/Cu composite by internal-oxidation

Cu-0.6%Zr (mass fraction) alloy powders were prepared by using high-pressure water atomization with non-vacuum melting, and ZrO₂/Cu in-situ reinforced composite was prepared after particle size separation, following by low-temperature oxidation, N₂+5%H₂ (volume fraction) mixture reduction and vacuum spark plasma sintering(SPS) forming. The results show that lower temperature leads to lower oxidation rate, while higher temperature leads to over oxidation and agglomeration, and the ideal oxidation parameter is 230℃×1 h; In N₂+5%H₂ gas flow of 200 mL/min, the best reduction parameter is 250℃×1 h which is measured by hydrogen-annealed experiment; Under the condition of 30 MPa, 850℃×2 h vacuum SPS, the typical performance of the ZrO₂/Cu sample has been obtained that the conductivity is higher than 83% IACS(international annealed copper standard), the hardness is higher than HB 75 and the softening temperature is 900℃.