魏氏组织TC17钛合金绝热剪切带(ASB)的组织与织构

Microstructure and Texture of Adiabatic Shear Band(ASB) in TC17 Titanium Alloy with Widmanstatten Microstructure

利用热模拟试验机对原始组织为魏氏组织的TC17钛合金进行了热压缩试验,采用电子背散射衍射技术(EBSD)研究了不同变形参数对魏氏组织TC17钛合金材料显微组织与结构的影响。结果表明:在700℃以上进行热压缩变形时,魏氏组织TC17钛合金的材料均发生绝热剪切行为,所形成的ASB中心区域组织主要由动态再结晶形成的等轴状β相晶粒和少量α相组成。随变形温度升高,残余α相略有增加,β相晶粒尺寸增大。不同变形参数对于ASB中心区域β相的取向分布影响甚微,在β相中主要形成高斯织构。同时绝热剪切敏感性的研究表明,魏氏组织TC17钛合金具有较高的绝热剪切敏感性,且随变形温度升高,绝热剪切敏感性增强。

Hot compression tests were carried out on TC17 titanium alloy with Widmanstatten microstructure by thermal simulation testing machines,and the influence of different deformation parameters on the morphology and structure of the TC17 titanium alloy was characterized by electron back scattered diffraction（EBSD） techniques.The results show that adiabatic shear band（ASB） occurs in the TC17 alloy with Widmanstatten microstructure while the hot compression deformation temperature is over 700 °C,and the central region of ASB is mainly composed of equiaxed β-phase grains formed by dynamic re-crystallization and a small amount of α-phase.More residual α phase appears and the β-phase grain size increases with increasing of the hot compression temperature.Different deformation parameters have little effect on the orientation distribution of β-phase in the central region of ASB,and Goss texture mainly forms in β-phase.Furthermore,the TC17 titanium alloy with Widmanstatten microstructure has good adiabatic shear sensitivity,and it increases gradually with the increase of hot compression deformation temperature.