烧结温度对高速压制制备弥散强化铜材料导电率的影响

Influence of sintering temperature on the electrical conductivity of Al_2O_3/Cu composites compacted by high velocity compaction

弥散强化铜材料具有高强度和高导电性的特性,孔洞是影响导电率的重要因素.本文采用高速压制成形技术,对Al2O3质量分数为0.9%的弥散强化铜粉压制成形,研究了压制速度对生坯的影响.当压制速度为9.4 m·s-1时得到密度为8.46 g·cm-3的生坯.研究了烧结温度对烧结所得Al2O3弥散强化铜试样导电率的影响.当生坯密度相同时,烧结温度越高,所得试样的导电率也越高.断口与金相分析表明:烧结温度为950℃时,烧结不充分,颗粒边界以及孔洞多而明显,孔洞形状不规则;烧结温度为1080℃时,颗粒边界消失,孔洞圆化,韧窝出现,烧结坯的电导率为71.3%IACS.

Oxide dispersion strengthening（ ODS） copper has the characteristics of both high strength and high conductivity. The porosity is an important factor influencing the electrical conductivity. 0. 9Al2O3/ Cu powder was compacted by a high velocity compaction（ HVC） technique. The influence of impact velocity on the green density of Al2O3 dispersion strengthening copper was studied,and the green density of 8. 46 g·cm-3was got at the impact velocity of 9. 4 m·s-1. The dependence of the electrical conductivity on sintering temperature was investigated. The results from sintering steps showed that the higher the sintering temperature was,the higher the electrical conductivity was at the same green density level. Fracture surface and SEM observations indicated that the samples were inadequately sintered at the sintering temperature of 950 ℃,with particle boundaries and some pores being visible obviously. When the sintering temperature rose up to 1080 ℃,the pores tended to spheroidize,the particle boundaries disappeared,and the dimples appeared on the fracture surface,showing a typical plastic fracture characteristic. The electrical conductivity of the sintered compacts was measured to be 71. 3% IACS.