塑性变形对TiNbTaZr合金微观结构的影响

Influence of Plastic Deformation on Microstructure of TiNbTaZr Alloy

用透射电子显微镜对不同轧制变形量的TiNbTaZr合金进行观察分析,结果表明:该合金轧制前为单相β相,轧制后出现应力诱发马氏体α"相,变形主要以位错-滑移为主,有少量马氏体α"相形成,马氏体α"相为正交晶系,单胞参数a=0.3152 nm,b=0.4854 nm,c=0.4642 nm;β相与马氏体α"相的位向关系为(011)β//(010)α″,(011)β//(002)α″,(100)β//(100)α″,[100]β//[100]α″。硬度检测表明:TiNbTaZr合金的硬度值随变形量的增大而增加,变形过程中形成的高密度位错是硬度值增大的主要原因。

The TiNbTaZr alloy after different rolling deformation was characterized by TEM.The results indicate that slip is the main mechanism for the rolling deformation,and stress-induced martensite is formed while only β phase exists before deformation.The martensite is orthorhombic α' phase,and its lattice parameters are a=0.315 2 nm,b=0.485 4 nm,c=0.464 2 nm.The misorientation between β phase and α' phase are (011)β(010)α″,(011)β(002)α″,(100)β(100)α″,[100]β[100]α″.The microhardness of the deformed alloy is increased with the increase of the deformation extent,and high density dislocations induced by the deformation is the reason of microhardness increasement.