SEBM成形片状极小曲面点阵材料的力学性能  

Mechanical Property of Shell Minimal Surface Lattice Material Printed by SEBM

作　　者：樊永霞 王建[1] 张学哲 王建忠[1] 汤慧萍[1] FAN Yongxia;WANG Jian;ZHANG Xuezhe;WANG Jianzhong;TANG Huiping(State Key Laboratory of Porous Metal Materials,Northwest Institute for Nonferrous Metal Research,Xi'an 710016,China)

机构地区：[1]西北有色金属研究院金属多孔材料国家重点实验室,西安710016

出　　处：《金属学报》2021年第7期871-879,共9页Acta Metallurgica Sinica

基　　金：国家自然科学基金项目Nos.51829401,51627805。

摘　　要：以球形Ti-6Al-4V合金粉末为原料,采用电子束选区熔化(selective electron beam melting,SEBM)技术制备了片状三周期极小曲面(triply periodic minimal surface,TPMS)点阵材料以及桁架点阵材料,研究了点阵材料的成形质量、显微组织及压缩性能。成形结果表明,SEBM成形片状TPMS和桁架点阵材料尺寸精度在电子束束斑直径范围之内,与计算机辅助设计(computer aided design,CAD)模型具有较好的几何一致性;SEBM成形Ti-6Al-4V点阵材料的微观组织为原始粗大β柱状晶,晶内为细小正交的α’马氏体组织以及细小α+β组织;TPMS点阵材料较桁架点阵材料表现出优越的力学性能,其中,金刚石(D)型点阵材料在TPMS点阵材料中具有最高的压缩强度,其比抗压强度可达146.9 MPa/(g·cm^(-3)),远高于相同相对密度下桁架点阵材料的最高比抗压强度119.6 MPa/(g·cm^(-3))。Lightweight and strong lattice materials are suitable for a wide range of applications in aerospace,automotive,biomedical,shipbuilding,and a variety of other significant industries.A class of mathematically defined surfaces that exhibit three-dimensional(3 D)periodicity,zero mean curvature,and large surface area is the triply periodic minimal surface(TPMS).Inspired by natural systems,such as biological cubic membranes,sea urchins,and butterfly wing scales,TPMS lattice material is composed of continuous and smooth shells,allowing for decreased stress concentration by comparison with strutbased lattice material.In this study,strut-based lattice materials,namely octet-truss(O)and tetrakaidecahedral(T),shell-based lattice materials,namely Diamond(D);Gyroid(G);and I-WP(I),and Primitive(P)lattice materials,were rationally designed and manufactured using Ti-6 Al-4 V alloy powder by selective electron beam melting(SEBM)process.The discrepancies between the design and manufactured diameters or thicknesses,optical microstructures,and mechanical properties of these lattice materials have been defined in detail.The results showed that the variations between the design and manufactured diameter or thickness of SEBM manufactured lattice materials were smaller than the value of the electron beam spot diameter,showing good geometric consistency with the original computer-aided design models.Due to the high thermal gradients and rapid cooling rates observed in the SEBM process,the resulting microstructure of lattice materials was columnar priorβgrains,which were parallel to the build direction,where inside the columnarβgrains wereα+βand martensiteα’platelets.The key finding is that TPMS lattice materials exhibit superior mechanical properties compared to strut-based lattice materials in compressive strength,elastic modulus,and plasticity,owning to their smooth and continuous surface.Among the SEBM manufactured shell-based lattice materials,the mechanical properties of type D lattice materials perform best.Moreover,the spec

关 键 词：三周期极小曲面 电子束选区熔化 TI-6AL-4V 点阵材料 

分 类 号：TG146.2[一般工业技术—材料科学与工程]