【摘要】 采用粉末冶金(PM)热等静压(HIP)法以Ta-W-Hf预合金粉末为原料制备了致密块体材料及进行高温处理,测量了材料晶内和晶界处的显微硬度,分析了氧和铪元素的分布状态。结果表明,制备的Ta-W-Hf合金无论退火与否,晶界的硬度均大于晶粒内的硬度。高温退火降低了材料的整体硬度和强度,但仍高于相同成分的熔炼加工材,且韧性与熔炼加工材相当。较高的晶界硬度是由于氧和铪元素的偏聚分布及富氧富铪小粒子的析出所致。更多还原

【Abstract】 The pre-alloying Ta-W-Hf powder was HIPed to obtain the dense bulk. The strengthening and grain boundary hardening for the Ta-W-Hf alloy prepared by powder metallurgy were investigated. The mechanical properties, microhardness at different zones as well as the distribution of oxygen and hafnium element were tested and analysized. It is shown that the hardness of grain boundary for the alloy annealed or not, are higher than those of inner grain, resulting from the segregative distribution and the precipitation of oxygen and hafnium enriched particles. The integral hardness and strength of Ta-W-Hf alloy by HIP decreases after annealing, but ore higher than those by electron beam melting/thermal mechanical processing. The toughness of the two sorts of Ta alloys are approximately the same.更多还原