Influences of boron contents on microstructures and mechanical properties of as-casted nearαtitanium alloy  

作　　者：Xiaozhao Ma Zhilei Xiang Chao Tan Zhitian Wang Yingying Liu Ziyong Chen Qun Shu 

机构地区：[1]College of Materials Science and Engineering.Beijing University of Technology,Beijing 100124,China [2]Aviation Industry of China(AVIC)Manufacture Technology Institute,Beijing 100024,China

出　　处：《Journal of Materials Science & Technology》2021年第18期1-18,共18页材料科学技术（英文版）

基　　金：the Industrial Strengthen Foundation Project of Ministry of Industry and Information Technology,PRC(No.TC150B5C0-02)。

摘　　要：Ti-6.5 Al-2.5 Sn-9 Zr-0.5 Mo-0.25 Si-1 Nb-1 W-0.1 Er-x B(x=0,0.1,0.2,0.4,0.6 and 0.8 wt%)with different boron contents are fabricated for investigation.Influences of boron element and its amounts on phase constitutions,microstructures,textures and compression mechanical properties are carefully studied.With the increasing boron additions,contents of TiB phase increase,and the maximum intensities of textures decrease.Microstructures are significantly and continuously refined after adding boron element and with the increasing boron additions,and turning point of refinement rates for different microstructural parameters is found at 0.2 wt%boron content.Strengths increase monotonously,while elongations increase firstly and decrease afterwards.The maximum value of elongation is acquired at boron content of 0.2 wt%.On the premise of ensuring plasticity,0.2 wt%boron content is the most appropriate amount for microstructural refinement and mechanical properties enhancement for current nearαtitanium alloys.Meanwhile,aspect ratios of TiB whiskers increase with the increasing boron contents.Lots of near equiaxedαgrains orαgrains with irregular morphologies are discovered around TiB phase.Distorted and twistedαgrain boundaries are also obviously detected in boron containing alloys.Moreover,premature fracture of alloys containing TiB whiskers is largely influenced by the fracture of these brittle reinforcements.

关 键 词：Boron element Mechanical properties MICROSTRUCTURES Fracture behaviors Nearαtitanium alloy Textures 

分 类 号：TG146.23[一般工业技术—材料科学与工程]