Effect of porosity on mechanical properties of porous tantalum scaffolds produced by electron beam powder bed fusion  

孔隙率对电子束选区熔化多孔钽支架力学性能的影响

作　　者：Yu GUO Chao CHEN Qiang-bing WANG Min LIU Yuan-kui CAO Yan-ming PAN Li-ming TAN 郭瑜;陈超;汪强兵;刘敏;曹远奎;潘彦明;谭黎明(中南大学粉末冶金国家重点实验室,长沙410083;广州赛隆增材制造有限责任公司,广州510700;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)

机构地区：[1]State Key Laboratory of Powder Metallurgy,Central South University,Changsha 410083,China [2]Guangzhou Sailong Additive Manufacturing Co.,Ltd.,Guangzhou 510700,China [3]State Key Laboratory of Porous Metal Materials,Northwest Institute for Nonferrous Metal Research,Xi’an 710016,China

出　　处：《Transactions of Nonferrous Metals Society of China》2022年第9期2922-2934,共13页中国有色金属学报（英文版）

基　　金：supported by the Key R&D Program of Guangdong Province,China(Nos.2019B090904001,2018B090906003)。

摘　　要：The effect of porosity on compressive,bending,and tensile properties of the porous tantalum scaffolds fabricated by electron beam powder bed fusion(EB-PBF)was investigated.The porous tantalum scaffolds with porosity from 69%to 77.8%were obtained by varying the designed porosity and adjusting the processing parameters.It is found that the pores and unfused powder decrease with the increase of deposited energy density.The decrease of porosity leads to an improvement in mechanical properties.The relevancy between compressive/bending/tensile yield strength and relative density can be described appropriately by exponential model,while the relationship between elastic modulus and relative density is in good agreement with the Gibson-Ashby model.All the porous tantalum scaffolds exhibit good ductility in compressive,bending and tensile tests.No fragmentation of struts is observed during the compression process,but cracks are formed on the strut surface after 90°bending,mainly due to the high sensibility to defects caused by the oxide.研究了孔隙率对电子束选区熔化(EB-PBF)多孔钽支架压缩、弯曲和拉伸性能的影响。通过改变多孔钽支架设计孔隙率以及调整熔化工艺参数,获得了孔隙率为69%~77.8%的多孔钽支架。研究表明,随着能量密度的增加,多孔钽支架中的孔洞和未熔融粉末减少。随着孔隙率的下降,多孔钽支架的力学性能增加。EB-PBF多孔钽支架压缩屈服强度、弯曲屈服强度以及拉伸屈服强度与相对密度的关系可以用指数模型来描述,弹性模量则与相对密度较好地符合Gibson-Ashby模型。多孔钽支架在压缩、弯曲和拉伸试验中均表现出良好的延性,在压缩过程中没有发现杆筋断裂,但在90°弯曲后,多孔钽杆筋表面出现裂纹,这主要是由于对氧化物引起的缺陷具有较高的敏感性。

关 键 词：porous tantalum scaffold electron beam powder bed fusion POROSITY mechanical properties Gibson−Ashby model 

分 类 号：R318[医药卫生—生物医学工程] TG146.416[医药卫生—基础医学]