摘要
基于团簇式设计方法,采用激光增材制造工艺制备一种近α型Ti-7Al-2V合金,其比强度优于Ti-6Al-4V合金的比强度。该合金的成分式为α-{[Al-Ti_(12)](AlTi_(2))}_(15)+β-{[Al-Ti_(14)](V_(3))}_(2):其特征在于α结构单元比例提高为15/17(相对于Ti-6Al-4V的12/17),使合金成分偏向α-Ti;通过V元素合金化,提高了β-Ti结构单元稳定性。该合金具有良好的激光增材制造成形性。沉积态下,该合金的显微组织由细网篮组织区、粗网篮组织区和超细α魏氏组织区构成。其中,粗网篮组织区的表面粗糙度明显低于细网篮组织区和超细α魏氏组织区的表面粗糙度。细网篮组织区的α相分布相比于粗网篮组织区更加均匀。该合金的抗拉强度为971~1005 MPa,屈服强度为891~921 MPa,伸长率为4.5%~6.6%,均与Ti-6Al-4V的相近,尤其是该合金的比强度为224~232 kN·m/kg,优于Ti-6Al-4V合金的比强度。
A near-αTi-7Al-2V alloy was designed using cluster formula approach and prepared by laser additive manufacturing,whose specific strength is better than that of Ti-6Al-4V alloy.Its composition formulaα-{[Al-Ti_(12)](AlTi_(2))}_(15)+β-{[Al-Ti_(14)](V_(3))}_(2) features an enhancedα-Ti by increasingαunit proportion of 15/17(with respect to 12/17 of Ti-6Al-4V alloy)and stabilizedβ-Ti via V alloying.This alloy possesses a good laser additive manufacturing processibility.At the as-deposited state,the microstructures are composed of fine basket-weave regions,coarse basket-weave regions and ultrafineαWidmanstätten lath regions.The surface roughness of coarse basket-weave regions is much smaller than that of fine basket-weave regions and ultrafineαWidmanstätten lath regions.Theα-phase distribution in fine basket-weave regions is more uniform than that in the coarse basket-weave regions.Its ultimate tensile strength of 971-1005 MPa,yield strength of 891-921 MPa and elongation of 4.5%-6.6%are close to those of Ti-6Al-4V alloy,and particularly,its specific strength of 224-232 kN·m/kg is better than that of Ti-6Al-4V alloy.
作者
朱智浩
刘田雨
宋梦凡
陈志鹏
张爽
董闯
Zhi-hao ZHU;Tian-yu LIU;Meng-fan SONG;Zhi-peng CHEN;Shuang ZHANG;Chuang DONG(Key Laboratory for Materials Modification by Laser,Ion,and Electron Beams of Ministry of Education,School of Materials Science and Engineering,Dalian University of Technology,Dalian 116024,China;State Key Laboratory of Light Alloy Casting Technology for High-end Equipment,Shenyang Research Institute of Foundry Co.,Ltd.,Shenyang 110022,China;School of Materials Science and Engineering,Dalian Jiaotong University,Dalian 116028,China)
基金
supported by the Key Discipline and Major Project of Dalian Science and Technology Innovation Foundation,China(No.2020JJ25CY004)
the National Basic Research Program of China(No.2020JCJQZD165)。
关键词
钛合金
成分设计
团簇加连接原子模型
激光增材制造
力学性能
Ti alloy
composition design
cluster-plus-glue-atom model
laser additive manufacturing
mechanical properties
