Choi Hyelim, Shil'ko Serge, Gubicza Jenő, Choe Heeman
School of Materials Science and Engineering, Kookmin University, 77 Jeongneung-ro, Seongbuk-gu, Seoul 20707, Republic of Korea.
V.A. Belyi Metal-Polymer Research Institute of National Academy of Sciences of Belarus, 32A Kirov Str., 246050 Gomel, Belarus.
J Mech Behav Biomed Mater. 2017 Aug;72:66-73. doi: 10.1016/j.jmbbm.2017.04.020. Epub 2017 Apr 21.
Ti and Ti‒5wt% W alloy foams were produced by freeze-casting process and their mechanical behaviors were compared. The Ti‒5W alloy foam showed a typical acicular Widmanstätten α/β structure with most of the W dissolved in the β phase. An electron-probe microanalysis revealed that approximately 2wt% W was uniformly dissolved in the Ti matrix of Ti‒5W alloy foam with few partially dissolved W particles. The compressive-yield strength of Ti‒5W alloy foam (323MPa) was approximately 20% higher than that of the Ti foam (256MPa) owing to the solid-solution-strengthening effect of W in the Ti matrix, which also resulted in a dramatic improvement in the wear resistance of Ti‒5W alloy foam. The compressive behaviors of the Ti and Ti‒5W alloy foams were predicted by analytical models and compared with the experimental values. Compared with the Gibson-Ashby and cellular-lattice-structure-in-square-orientation models of porous materials, the orientation-averaging method provided prediction results that are much more accurate in terms of both the Young's modulus and the yield strength of the Ti and Ti‒5W alloy foams.
通过冷冻铸造工艺制备了钛及Ti-5wt%W合金泡沫，并对它们的力学行为进行了比较。Ti-5W合金泡沫呈现出典型的针状魏氏组织α/β结构，大部分W溶解在β相中。电子探针微分析表明，约2wt%的W均匀溶解在Ti-5W合金泡沫的Ti基体中，仅有少量部分溶解的W颗粒。由于W在Ti基体中的固溶强化作用，Ti-5W合金泡沫的抗压屈服强度（约323MPa）比钛泡沫（约256MPa）高出约20%，这也使得Ti-5W合金泡沫的耐磨性得到显著提高。通过解析模型预测了钛及Ti-5W合金泡沫的压缩行为，并与实验值进行了比较。与多孔材料的吉布森-阿什比模型和方形取向的蜂窝晶格结构模型相比，取向平均法在预测钛及Ti-5W合金泡沫的杨氏模量和屈服强度方面提供了更为准确的结果。
