Deformation mechanisms during superplastic testing of Ti-6Al-4V-0.1B alloy

详细信息    查看全文

• 作者：Shibayan Roy ; Satyam Suwasp> ; p>p>satyamsuwas@materials.iisc.ernet.inp>p> ; p>p>satyamsuwas@gmail.comp>
• 关键词：Ti&ndash ; 6Al&ndash ; 4V&ndash ; 0.1B alloy ; Superplasticity ; Microstructure ; Texture ; Boundary sliding ; Cavitation
• 刊名：Materials Science and Engineering: A
• 出版年：2013
• 出版时间：1 July, 2013
• 年：2013
• 卷：574
• 期：Complete
• 页码：205-217
• 全文大小：2929 K

文摘

Superplastic tensile tests on warm rolled and optimally annealed boron modified alloy Ti-6Al-4V-0.1B at a temperature of 850 ¡ãC and initial strain rate of 3¡Á10p>?4p> sp>?1p> results in a higher elongation (¡«500 % ) compared to the base alloy Ti-6Al-4V (¡«400 % ). The improvement in superplasticity has been attributed to enhanced contribution from interfacial boundary sliding to the overall deformation for the boron modified alloy. The boundary sliding was facilitated by the starting microstructure which predominantly contains small equiaxed primary ¦Á grains with narrow size distribution. Dynamic processes such as coarsening and globularization of primary ¦Á phase occur under the test condition but do not significantly contribute to the observed difference in superplasticity between the two alloys. In spite of cavitation takes place around the TiB particles during deformation, they do not cause macroscopic cracking and early fracture by virtue of the cavities being extremely localized. Localized cavitation is found to correlate with increased material transfer due to faster diffusion.