Compressive and fatigue behavior of beta-type titanium porous structures fabricated by electron beam melting
Compressive and fatigue behavior of beta-type titanium porous structures fabricated by electron beam melting
复制标题
电子束熔炼β型钛多孔结构的压缩和疲劳行为
DOI：
10.1016/j.actamat.2016.12.052
复制
发表时间：
2017-03-01
期刊：
影响因子：
9.4
通讯作者：
Zhang, L. C.
中科院分区：
文献类型：
--
作者：
Liu, Y. J.;Wang, H. L.;Zhang, L. C.
β型钛多孔结构是一种新型的植入物解决方案，因为它提供了高强度和低杨氏模量的优异组合。本文研究了电子束熔炼（EBM）制备的β型Ti 2448合金样品中孔隙率的变化对力学性能（包括超弹性性能、杨氏模量、压缩强度和疲劳性能）的影响。观察了相邻晶粒取向差角与疲劳裂纹偏转行为的关系。由于拉压比的增加，材料的超弹性性能随着孔隙率的增加而提高。首次根据疲劳循环回路的变化确定了疲劳裂纹萌生位置。EBM独特的制造工艺导致了不同尺寸晶粒的产生，并且由于相邻晶粒之间的大量取向差，在柱状晶区的晶界处发生明显的疲劳裂纹偏转。与Ti-6Al-4V样品相比，Ti 2448多孔样品由于超弹性性质、疲劳裂纹尖端前更大的塑性区和裂纹偏转行为而表现出更高的归一化疲劳强度。(C)2016 Acta Materialia Inc.由爱思唯尔有限公司出版。保留所有权利。
beta-type titanium porous structure is a new class of solution for implant because it offers excellent combinations of high strength and low Young's modulus. This work investigated the influenceof porosity variation in electron beam melting (EBM)-produced beta-type Ti2448 alloy samples on the mechanical properties including super-elastic property, Young's modulus, compressive strength and fatigue properties. The relationship between the misorientation angle of adjacent grains and fatigue crack deflection behaviors was also observed. The super-elastic property is improved as the porosity of samples increases because of increasing tensile/compressive ratio. For the first time, the position of fatigue crack initiation is defined in stress-strain curves based on the variation of the fatigue cyclic loops. The unique manufacturing process of EBM results in the generation of different sizes of grains, and the apparent fatigue crack deflection occurs at the grain boundaries in the columnar grain zone due to substantial misorientation between adjacent grains. Compared with Ti-6Al-4V samples, the Ti2448 porous samples exhibit a higher normalized fatigue strength owing to super-elastic property, greater plastic zone ahead of the fatigue crack tip and the crack deflection behavior. (C) 2016 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.