Twinning Behavior of a Basal Textured Commercially Pure Titanium Alloy TA2 at Ambient and Cryogenic Temperatures

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• 作者：Jin-ru LUO ^{luojr@ustb.edu.cn" class="auth_mail" title="E-mail the corresponding author}Author Vitae ; Xiao SONG ; Lin-zhong ZHUANG ; Ji-shan ZHANG
• 关键词：titanium ; rolling ; twinning ; cryogenic temperature
• 刊名：Journal of Iron and Steel Research, International
• 出版年：2016
• 出版时间：January 2016
• 年：2016
• 卷：23
• 期：1
• 页码：74-77
• 全文大小：1295 K

文摘

Twinning greatly affects the microstructure and mechanical performance of titanium alloys. The twinning behavior of a basal textured commercially pure titanium TA2 plates rolled to 4% reduction at the ambient and cryogenic temperatures has been investigated. Microstructures of the rolled samples were investigated by optical microscope (OM) and the twinning analysis was carried out based on orientation data collected by electron back-scatter diffraction (EBSD). {11ge" height="12" width="7" alt="Full-size image (8 K)" title="Full-size image (8 K)" src="/sd/grey_pxl.gif" data-inlimgeid="1-s2.0-S1006706X16300152-fx1.jpg">2} contraction twins, {11ge" height="12" width="7" alt="Full-size image (8 K)" title="Full-size image (8 K)" src="/sd/grey_pxl.gif" data-inlimgeid="1-s2.0-S1006706X16300152-fx1.jpg">4} contraction twins and {10ge" height="13" width="7" alt="Full-size image (8 K)" title="Full-size image (8 K)" src="/sd/grey_pxl.gif" data-inlimgeid="1-s2.0-S1006706X16300152-fx2.jpg">2} extension twins have been observed. Twinning mode activity varied with rolling temperature. Twinning is considered as the dominant deformation mechanism during rolling at both temperatures for the strain condition. Larger proportion of grains activates twinning during cryorolling, and greater number and more diverse types of twins are observed; manifestly related to the suppression of dislocation slips at the cryogenic temperature. {11ge" height="12" width="7" alt="Full-size image (8 K)" title="Full-size image (8 K)" src="/sd/grey_pxl.gif" data-inlimgeid="1-s2.0-S1006706X16300152-fx1.jpg">2} contraction twins are the dominate twin type within samples rolled at both temperatures. Several {11ge" height="12" width="7" alt="Full-size image (8 K)" title="Full-size image (8 K)" src="/sd/grey_pxl.gif" data-inlimgeid="1-s2.0-S1006706X16300152-fx1.jpg">4} contraction twins are observed in the cryorolled sample while there are only a few in the sample rolled at room temperature. A few tiny {10ge" height="13" width="7" alt="Full-size image (8 K)" title="Full-size image (8 K)" src="/sd/grey_pxl.gif" data-inlimgeid="1-s2.0-S1006706X16300152-fx2.jpg">2} twins have been identified in both samples. {11ge" height="12" width="7" alt="Full-size image (8 K)" title="Full-size image (8 K)" src="/sd/grey_pxl.gif" data-inlimgeid="1-s2.0-S1006706X16300152-fx1.jpg">4} contraction twins are preferentially activated at cryogenic deformation temperature and the {10ge" height="13" width="7" alt="Full-size image (8 K)" title="Full-size image (8 K)" src="/sd/grey_pxl.gif" data-inlimgeid="1-s2.0-S1006706X16300152-fx2.jpg">2} extension twins may result in local strain accommodation.