微织构对Ti150合金锻件拉伸性能的影响

Effect of Micro-texture on Tensile Properties of Ti150 Alloy Forging

利用光学显微镜(OM)、扫描电子显微镜(SEM)和电子背散射衍射(EBSD)等研究了Ti150合金锻件3个典型位置处的显微组织、微织构和拉伸性能。结果表明,锻件心部存在强微织构,表现为由晶体取向相近晶粒组成的条带状“宏区”,边缘和弧面等靠近外轮廓区域的微织构较弱;微织构较强区域的β转变组织内次生α相呈平行排列的集束状,而微织构较弱区域的次生α相呈编织排列;条带状“宏区”和β转变组织中的集束状次生α相均相当于粗大晶粒,增大了位错滑移距离,界面强化效应减弱,导致锻件心部的强度明显低于靠近外轮廓的区域。

The microstructure,micro-texture and tensile properties of Ti150 alloy forging were researched by optical microscope(OM),scanning electron microscope(SEM),electron back-scattered diffraction(EBSD)and ect.The results indicate that there is a strong micro-texture in the center of the forging,which is characterized by banded grains with similar crystal orientation,while the micro-texture in the regions close to the outer contour such as the edge and camber surface is weak.The secondaryαphase in the transformedβphase with strong micro-texture is arranged in parallel cluster structure while the secondaryαphase in the weak texture region is arranged with net structure.The structures of band-like macro-region and cluster secondaryαphase in transformedβphase are equivalent to coarse grains,which increase the dislocation sliding distance and decrease the interface-strengthening effect.So the tensile strength in the center of Ti150 alloy forging is significantly lower than that in the outer countour region.