ABSTRACT

Electron beam melted (EBM) Ti-6Al-4V functionally graded materials (FGM) with continuously graded densities are investigated for dimensional accuracy, compressive properties, fractography and build direction effect in comparison to uniform density counterparts of the same volume. It is found that FGMs exhibit progressive layer-by-layer deformation mode regardless of unit cell designs and build direction. This deformation behavior is highly favourable for uni-directional impact absorption applications compared to uniform density counterparts with random or diagonal failure. Overall, the EBM-built FGM exhibits superior energy absorption than counterparts of uniform density. Significant improvement in the quasi-elastic gradient and energy absorption is obtained by changing the build direction for specific designs. Compared with other FGM or uniform density lattice structures from the literature, the energy absorption of lattice structures with lower relative density could outperform those with higher relative density by changing the unit cell design or density profile.

摘要

研究了具有连续梯度密度的电子束熔化（EBM）Ti-6Al-4V功能梯度材料（FGM）的尺寸精度，压缩性能，分形和与相同体积的均等密度对应物相比的构造方向效应。已经发现，FGM表现出渐进的逐层变形模式，而与晶胞设计和构建方向无关。与具有随机或对角线破坏的均匀密度对应物相比，这种变形行为对于单向冲击吸收应用非常有利。总体而言，由EBM制造的FGM比均匀密度的同类材料具有更高的能量吸收能力。通过更改特定设计的构建方向，可以显着改善准弹性梯度和能量吸收。