基于选区激光熔化的Ti-6Al-4V钛合金节点增强型点阵结构及其力学行为

    Ti-6Al-4V Node-enhanced Lattice Structure Prepared by Selective Laser Melting and Its Mechanical Behavior

    • 摘要: 以Ti-6Al-4V钛合金粉末为原材料,采用选区激光熔化技术制备了常规和节点增强型体心四方点阵结构。研究了两种点阵结构的形貌、微观结构及力学性能。并探究了常规热处理对节点增强型点阵结构微观结构及力学性能的影响。结果表明,在节点处提高制备激光功率后该处直径增大,节点处表面粗糙度及孔隙率值均增大,整体结构相对密度提高24.8%,节点处初生β晶发生了等轴化。增强后的点阵结构失效由贯穿整体的斜60°瞬间坍塌模式转变为逐层沉降式坍塌模式,比弹性模量增加了112%,比抗压强度增加了52%,30%应变时的比吸能提升了88%,整体力学性能有了显著提升。热处理后节点增强型点阵结构抗压强度下降,但能量吸收能力得到了提高。

       

      Abstract: Taking Ti-6Al-4V titanium alloy powder as the raw material, conventional and node-enhanced body-centered tetragonal lattice structures were prepared by using selective laser melting.The morphology, microstructure and compression properties of the two lattice structures were studied.And the influence of conventional heat treatment on the microstructure and mechanical properties of the node-enhanced lattice structure was explored.The results show that after increasing the laser power at the nodes, the diameter at the nodes increases and the surface roughness and porosity of the material both increase, the relative density increases by 24.8% and the prior β grains at the nodes become equiaxed.The failure mode of enhanced lattice structure changes from the 60° instantaneous collapse mode throughout the whole structure to the layer-by-layer sedimentation collapse mode, the specific elastic modulus increases by 112%, the specific compressive strength increases by 52%, and the specific energy absorption at 30% strain increases by 88%, the whole mechanical properties are improved dramatically.After heat treatment, the compressive strength of the node-enhanced lattice structure decreases, but its energy absorption capacity is improved.

       

    /

    返回文章
    返回