微观组织对Ti-6Al-4V-4Zr-1.5Mo合金绝热剪切敏感性的影响

对锻造态Ti-6Al-4V-4Zr-1.5Mo合金采用不同的热处理工艺得到等轴、双态和网篮3种组织。使用分离式Hopkinson Bar技术对3种组织的试样进行动态剪切试验,研究了不同微观组织对该合金绝热剪切敏感性的影响。结果表明:当加载条件高于其临界应变率时,不同组织试样的承载时间均随着应变率的提高而降低;微观组织对该合金的绝热剪切敏感性影响较大,网篮组织绝热剪切敏感性最低,双态组织绝热剪切敏感性最高;双态组织剪切带附近基体相界处出现微裂纹,是造成其易于发生剪切破坏的主要原因。

Effects of Microstructure on the Adiabatic Shear Banding Sensitivity of Ti-6Al-4V-4Zr-Mo Alloy

An examination of the effects of microstructures on the adiabatic shear banding sensitivity of Ti-6Al-4V-4Zr-Mo alloy was reported.Using the technology of split Hopkinson bar,the dynamic shearing experiments on Ti-6Al-4V-4Zr-Mo alloy with different heat treatments were conducted.The obtained microstructures are divided into the lamellar,the equiaxed and the bimodal according to heat-treatment conditions.The results indicate that the lamellar microstructure has the lowest adiabatic shear banding sensitivity,while the bimodal microstructure has the highest.In the bimodal microstructure,small cracks are found in the α/β interface located in the matrix region near the adiabatic shear band,which is considered as the main reason why the bimodal ones have the highest adiabatic shear banding sensitivity.