微量Sc对TiAl基合金显微组织和力学性能的影响  

Influence of trace Sc addition on mechanical properties and microstructure of TiAl base alloy

作　　者：金头男[1] 尹志民[2] 李斗星[1] 

机构地区：[1]中国科学院金属研究所固体原子像开放研究实验室,沈阳110015 [2]中南工业大学材料科学与工程系,长沙410083

出　　处：《航空材料学报》2000年第4期8-13,共6页Journal of Aeronautical Materials

摘　　要：采用透射电子显微分析和力学性能测试方法研究了微量 Sc对 Ti Al合金显微组织和力学性能的影响。结果表明 ,合金的室温抗弯强度和最大挠度均随 Sc含量的增加而下降 ,而合金的高温压缩强度却显著提高。 TEM观察发现 ,Sc的加入使 Ti Al合金中形成大量的呈薄片或颗粒状的 (Sc,Ti) 3 Al相。这种相沿α2 /γ和γ/γT 界面择优分布 ,且与界面位错有交互作用。此种结构组态可能是造成 Ti Al合金的室温性能下降的主要原因。而对于以界面间的滑移为主要变形方式的高温形变 ,由于界面间的滑移受到阻碍作用 。The influence of trace Sc addition on the mechanical properties and the microstructure of TiAl base alloy were investigated. It is shown that the ambient fracture strength and the maximum deflection of the alloy decreased with the increase of Sc content. However trace Sc addition remarkably improve the high temperature yield strength of the alloy. Introducing of Sc to TiAl alloy leads to forming of a large amount of (Sc,Ti) 3Al phase particles, a newly found phase which distribute preferentially near the α 2/γ and γ/γ T interfaces. The obstacle to inter lamellar sliding due to (Sc,Ti) 3Al particles may be the main cause of the increase of high temperature strength of the alloy.

关 键 词：TIAI合金 SC 显微组织 力学性能 

分 类 号：TG146.21[一般工业技术—材料科学与工程] TG146.23[金属学及工艺—金属材料]