摘要
综述了钛铝金属间化合物晶团与片层尺寸效应研究进展,包括片层形成机制、晶团与片层尺寸控制方法,以及晶团尺寸、片层间距与力学性能之间的尺寸效应。研究结果表明,片层组织形成机制主要基于位错形核、剪切机制和原子偏析。单个γ相板条形成后,在母相中通过Shockley不全位错滑移及原子扩散生成不同取向的变体;晶团尺寸及片层间距,通过添加合金元素、相变/再结晶、热机械加工、粉末冶金等方式得到细化;晶团尺寸与硬度、强度符合经典的Hall-Petch关系,随晶团尺寸增加,屈服强度及硬度减小;晶团尺寸对断裂韧性影响复杂。片层间距与硬度、强度及断裂韧性也符合经典的Hall-Petch关系。高温蠕变最小应变速率及辐射后空洞密度随片层尺寸增大线性增大。
This review article summarized recent advances in size effect of lamellar colony and lamellar spacing in intermetallic titanium aluminides,including the formation mechanism of lamellar,methods of size controlling,and the present situation of size effect research. The formation mechanisms of fully lamellar Ti Al alloy were based on dislocation,shear and atomic segregation. γ variants interface formed by Shockley dislocation and atomic segregation after the formation of single γ lath. Phase transformation,recrystallization,even the thermo-mechanical processing and power metallurgy could be used to refine lamellar colony size and lamellar spacing.The hardness,strength,and other mechanical properties varied with the lamellar colony size of fully lamellar titanium aluminides within the scope of a certain size according to the typical Hall-Petch relationships. However,the colony size effect on fracture toughness was not clear. And allmost all of the mechanical properties such as hardness,strength,fracture toughness varied with the lamellar spacing within the scope of a certain size according to the typical Hall-Petch and minimum strain rate after creep at high temperature and cavity density had direct proportion relationships with lamellar spacing.
出处
《稀有金属》
EI
CAS
CSCD
北大核心
2016年第4期393-402,共10页
Chinese Journal of Rare Metals
基金
国家自然科学基金青年科学基金项目(51305304)
国家自然科学基金联合重点基金(U1302275)资助
国家科技重大专项课题(2013ZX04011061)
关键词
钛铝
全片层
尺寸效应
片层间距
titanium aluminides
fully lamellar
size effect
lamellar spacing
