退火温度对挤压态细晶钨合金性能及组织演变的影响  

Effect of Annealing Temperature on Mechanical Properties and Microstructure Evolution of the as-Extruded Fine-Grain Tungsten Alloy

作　　者：杨昌麟[1] 范景莲[1] 龚星[1] 丁飞[1] 刘涛[1] 

机构地区：[1]中南大学粉末冶金国家重点实验室,湖南长沙410083

出　　处：《稀有金属材料与工程》2013年第11期2293-2297,共5页Rare Metal Materials and Engineering

基　　金：国家杰出青年科学基金(50925416);国家自然科学基金创新群体项目(51074187)

摘　　要：采用稀土微合金化和液相强化烧结技术制备细晶93W-4.9Ni-2.1Fe+0.03%Y合金。研究在快速热挤压形变强化后,时效热处理对挤压态细晶93W-4.9Ni-2.1Fe+0.03%Y合金显微硬度和组织演变的影响,并与相应条件的传统钨合金进行对比。结果表明,随着退火温度的升高,2种钨合金钨相的显微硬度大大降低。EDS分析表明,随着退火温度的升高,钨合金粘结相中钨含量逐渐增加,其中细晶钨合金经过1200℃退火处理后,粘结相钨含量高达26.11%,而传统钨合金在1350℃退火处理后含量最高,达到28.14%。显微组织观察表明,退火有利于降低W-W连接度和细化钨颗粒;与传统钨合金相比,高温退火后,细晶钨合金的粘结相体积比更高且分布更为均匀。Fine-grain 93W-4.9Ni-2.1Fe＋0.03%Y alloy was fabricated by microalloying and liquid phase sintering process.The effects of the annealing temperature on the microhardness and microstructure evolution of the fine-grain 93W-4.9Ni-2.1Fe＋0.03%Y after rapid hot extrusion were investigated.Meanwhile,conventional tungsten heavy alloy was also fabricated at equivalent condition for comparison.The results show that the microhardness of tungsten phase of the alloys is severely decreased with the annealing temperature increasing.EDS examination reveals that the tungsten content in the matrix of tungsten heavy alloys is gradually enhanced with elevated annealing temperature.The tungsten content in the matrix of fine-grain tungsten heavy alloy has reached a maximum level of the order of 26.11% after annealed at 1200 ℃.While,the tungsten content in the matrix of conventional tungsten heavy alloy annealed at the temperature of 1350 ℃ is 28.14%.Microstructure observation shows that annealing treatment is preferential to the tungsten contiguity reduction and tungsten grain refinement.After high temperature annealing,the matrix is distributed more homogeneously and the volume fraction of the matrix of fine-grain tungsten heavy alloy is higher than that of coarse-grain alloy.

关 键 词：细晶钨合金 退火 显微硬度 显微组织 

分 类 号：TG156.2[金属学及工艺—热处理]