Effect of Microstructural Characteristics on Fracture Toughness in Direct Energy Deposited Novel Ti-6Al-4V-1Mo Alloy
作者机构：School of Material Science and EngineeringChang’an UniversityXi’an710064China Science and Technology on Plasma Dynamics LaboratoryAir Force Engineering UniversityXi’an710038China State Key Laboratory of Solidification ProcessingNorthwestern Polytechnical UniversityXi’an710072China Surface Material Protection Co.LtdXi’an710018China
出 版 物：《Acta Metallurgica Sinica(English Letters)》 (金属学报（英文版）)
年 卷 期：2024年第37卷第1期
页 面：119-131页
核心收录：
学科分类：08[工学] 0806[工学-冶金工程] 0802[工学-机械工程] 080201[工学-机械制造及其自动化]
基 金：This work was supported by the Key Research and Development Projects of Shaanxi Province(2023-YBGY-359) the China CEEC University Joint Education Project(2021108) the Science and Technology Plan of Xi'an City(21ZCZZHXJS-QCY6-0001,21CXLHTJSGG-QCY8-0003) the Open Fund of Key Laboratory of Plasma Dynamics of Air Force Engineering University(6142202210203).
主 题：Direct energy deposition Ti-6Al-4V-1Mo Tensile properties Fracture toughness Crack propagation
摘 要：Meeting the damage tolerance requirements for engineering-grade titanium alloys pose a significant challenge in achieving high fracture toughness in direct energy deposition(DED)titanium alloys.This work primarily investigated the relationship between the microstructure and the fracture toughness of DED new Ti-6Al-4V-1Mo alloy.Two types of microstructures were designed via two process strategies:high-line energy density(HE)and low-line energy density(LE).Relative to LE samples,HE samples possess larger-sized microstructural characteristics(coarser grain boundaryα(α_(GB)),largerαcolonies,and coarserαlaths).Lessα/βphase boundaries were formed by coarserαlaths in the HE samples,increasing the movement of dislocations,resulting in tensile strength decreasing from 1007.1 MPa(LE)to 930.8 MPa(HE)and elongation increasing from 10.8%(LE)to 15.7%(HE).Also,HE samples exhibited an excellent fracture toughness of 114.0 MPa m^(1/2),significantly higher than that of LE samples(76.8 MPa m^(1/2)).An analysis of crack propagation paths was conducted to investigate the factors contributing to toughening.The primary factor enhancing toughness is the frequent obstruction of cracks by coarseαGB and largeαcolonies in HE samples.Particularly,the pretty large-angle deflections induced by the superposition effect of coarseαGB and largeαcolonies play a vital of significant role.These factors induced the long and tortuous high-energy pathways,which resulted in ultimately improved fracture toughness.The discovered microstructural toughening mechanisms can serve as a reference for future studies involving titanium alloys,offering insights on how to enhance fracture toughness by achieving similar characteristics.
维普期刊数据库