Improvement of proof-ultimate strength difference in laser additive manufactured Ti-6Al-2V-1.5Mo-0.5Zr-0.3Si alloy by tuning basketweave structure

作     者：Guo-chao Li Xu Cheng Hua-ming Wang 

作者机构：National Engineering Laboratory of Additive Manufacturing for Large Metallic Components and Engineering Research Center of Ministry of Education on Laser Direct Manufacturing for Large Metallic Components School of Materials Science and Engineering Beihang University Beijing 100191 China Beijing Yuding Additive Manufacturing Research Institute Co. Ltd. Beijing 102206 China 

出 版 物：《Journal of Iron and Steel Research International》 (国际钢铁研究杂志)

年 卷 期：2019年第26卷第6期

页      面：631-636页

核心收录：

学科分类：0806[工学-冶金工程] 08[工学] 

基　　金：supported by the Beijing Natural Science Foundation(grant No.Z140002) Beijing Science and Technology Plan of China(grant No.Z17100000817002) 

主　　题：Titanium alloy Basket-weave structure Formation process a colony size Yield strength 

摘      要：After annealed at 1000 ℃, a special basket-weave structure is obtained in laser additive manufactured Ti-6Al-2V-1.5Mo- 0.5Zr-0.3Si alloy. The unit of the special basket-weave structure is a lamellas clusters, which consist of lamellar primary ot (otp), crab-like structures at the edges of otp and lamellar secondary a (as) on both sides of otp. As the units of basket-weave structures, the width of the clusters is much larger than that of a lamellas in as-deposited alloy. The formation temperature and process of the special basket-weave structure are studied, and the room temperature properties are tested and compared with the as-deposited alloy. The results show that the formation of the special basket-weave structure finishes within about 30 s and crab-like structures form earlier than lamellar as. The yield strength of the alloy is decreased by about 75 MPa compared to that of the as-deposited alloy. Besides, the proof-ultimate strength difference of the alloy is two times higher than that of the as-deposited alloy with about 34% improvement for the impact toughness. It is because ot colony size shows a positive correlation to the width of the unit forming basket-weave structure. The enhancement in proof-ultimate strengthdifference could significantly improve the toughness of the alloy, and thus effectively increase the safety of the alloy.