TiAl合金断裂韧性的影响因素及其韧化机制  

Influence Factors of TiAl Alloy Fracture Toughness and Toughening Mechanism

作　　者：宫子琪[1] 周峰[1] 柴丽华[1] 陈子勇[1] 相志磊[1] 聂祚仁[1] 

机构地区：[1]北京工业大学材料科学与工程学院,北京100124

出　　处：《材料科学与工程学报》2014年第3期465-468,451,共5页Journal of Materials Science and Engineering

基　　金：国家自然科学基金资助项目(51301005);北京市教委高层次人才培养资助项目(00900054R8002);北京工业大学博士科研启动基金资助项目(009000543113527)

摘　　要：TiAl基合金具有低密度、高比强度、高比刚度、良好的抗蠕变性能以及高温抗氧化性能等优点,成为一种很有希望的航空、航天及汽车用高温合金,但其断裂韧性低一直是阻碍TiAl基合金应用的重要原因。分析了TiAl基合金断裂韧性的主要影响因素,介绍了改善断裂韧性的主要途径,在此基础上概述了近年来关于TiAl合金韧化机制的论述,包括内在韧化和外在韧化机制。内在韧化来源于基体滑移和韧性相韧化,外在韧化机制起源于剪切韧带韧化、裂尖钝化、裂纹分叉、偏转和扩展、显微裂尖的屏蔽、孪晶韧化等。Titanium aluminides have been attracting significant attentions for their significant properties including low density,high strength,excellent creep resistance and oxidation resistance.These properties make them potential high temperature materials for aerospace and automobile. However,the fracture toughness is an obstacle to their practical applications.The main influence factors of the fracture toughness of TiAl alloy are analyzed and some methods that improve the alloy's fracture toughness are also introduced in this paper.Based on above,an overview on the toughening mechanism including inner and extrinsic toughening mechanism is summarized.Inner toughening comes from matrix slip and tough phases,while the extrinsic toughening originates from shear ligament toughing,crack tip blunting,crack branching,deflecting and propagation,microcrack tip shielding,and twin toughening,etc.

关 键 词：TIAL合金 断裂韧性 影响因素 韧化机制 

分 类 号：TG146.23[一般工业技术—材料科学与工程]