Al_2O_3颗粒增强Ag基复合材料的性能

为了克服Ag作为超导基底时的高温使用缺陷,提高Ag的熔点及其力学性能,选择了高熔点的Al2O3作为掺杂物,通过传统粉末冶金方法制备了Al2O3/Ag基复合材料.结果表明,在Ag基体中掺杂≥1%Al2O3粒子可以提高Ag的熔化温度tm至970℃以上,Al2O3质量分数大于3%时,样品tm可提高至990℃以上.在Al2O3质量分数小于3%样品中,2%Al2O3/Ag基复合材料具有最大的硬度、抗拉强度以及最小的线膨胀系数与延伸率.由于2%Al2O3/Ag样品具有合适的熔化温度、接近于YBaCuO的线膨胀系数和最好的力学性能,满足了后期Ar气氛下热处理YBaCuO超导带材对基底的要求.

Properties of Alumina-Particles-Reinforced Silver Composite

To overcome the high-temperature defects of Ag used as the substrate of superconducting tape and improve the mechanical properties and melting point of Ag, the alumina whose melting point is high was selected as a doping to prepare Al2O3/Ag composite through conventional powder metallurgy. The results indicated that over 1wt% Al2O3 particles doped in Ag matrix can raise the melting point tm of Ag up to 970°C and 3wt% Al2O3 particles can raise that up to 990°C. It was found that among the samples doped with Al2O3 particles less than 3wt%, the 2% Al2O3/Ag composite has the maximum hardness and tensile strength and minimum linear coefficient of expansion and elongation percentage. Since the sample 2% Al2O3/Ag composite has proper melting point, suitable linear coefficient of expansion in proximity to that of the YBaCuO superconductor and best mechanical properties, it meets the posterior heat-treatment requirements for YBaCuO superconducting tapes in Ar atmosphere.