航空学报 > 2004, Vol. 25 Issue (2): 201-204

热处理对Mo-Si系金属间化合物微观组织和断裂韧性的影响

杨海波, 李伟, 单爱党, 吴建生   

  1. 上海交通大学材料科学与工程学院高温材料及高温测试教育部重点实验室 上海 200030
  • 收稿日期:2003-03-17 修回日期:2003-06-10 出版日期:2004-04-25 发布日期:2004-04-25

The Effect of Heat-Treatment on Microstructure and Fracture Toughness of Intermetallics in Mo-Si System

YANG Hai-bo, LI Wei, SHAN Ai-dang, WU Jian-sheng   

  1. School of Material Science and Engineering, Shanghai Jiaotong University, Shanghai 200030, China
  • Received:2003-03-17 Revised:2003-06-10 Online:2004-04-25 Published:2004-04-25

摘要: 以纯金属Mo与纯Si为原料,通过电弧熔炼法制备了Mo3Si-Mo5Si3共晶,Mo5Si3-MoSi2亚共晶和过共晶Mo-Si系金属间化合物。在1200℃分别对3种合金进行了12h、24h、48h和96h真空退火,观察层状结构在合金中的形成、变化及破坏。1200℃退火48h后,在Mo5Si3-MoSi2亚共晶合金中发现了发展完好的Mo5Si3(D8m)/MoSi2(C11b)层状结构,层间距为几百纳米;在Mo5Si3-MoSi2过共晶合金中,层状结构的层间距与体积百分含量在退火前后没有发生明显变化;在Mo3Si-Mo5Si3共晶合金中始终未观察到层状结构的存在。通过压痕法测量了各合金的断裂韧性(KIC),研究了微观结构与KIC之间的关系。

关键词: 金属间化合物, 退火, 微观组织, 断裂韧性

Abstract: The Mo3Si-Mo5Si3 eutectic alloy , Mo5Si3-MoSi2 hypoeutectic alloy and hypereutectic alloy of Mo-Si system were prepared by arc-melting high purity elements of Mo-99.9 % and Si-99.99 %. The arc-melting buttonswere then annealed at 1200 ℃. The formation , alternation and destruction of lamellar structure were observed in alloys. After annealing at 1200 ℃for 48h , the well-developed lamellar structure consisting of Mo5Si3 (D8m) / MoSi2(C11b) with fine spacing of hundsed nanometer order was found in Mo5Si3-MoSi2 hypoeutectic alloy. The lamellarstructure did not change significantly before and after annealing in Mo5Si3-MoSi2 hypereutectic alloy. No lamellarstructure was observed in Mo3Si-Mo5Si3 eutectic alloy both before and after annealing. The fracture toughness( KIC) of alloys was determined by using Vickers indentation technique. The relationship between microstructureand KIC was investigated.

Key words: intermetallic, annealing, microstructure, fracture toughness