Strain rate sensitivity and high temperature deformation mechanisms of cast Zn-22Al alloy foams
Strain rate sensitivity and high temperature deformation mechanisms of cast Zn-22Al alloy foams
复制标题
铸造Zn-22铝合金泡沫的应变率敏感性和高温变形机制
DOI：
10.1016/j.mspro.2014.07.586
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发表时间：
2014
期刊：
影响因子：
--
通讯作者：
K. Kitazono and K. Sekido
中科院分区：
文献类型：
--
作者：
T. Ishimoto;K. Kawahara;J. Wang、H. Kamioka and T. Nakano;石松直樹，松島康晴，住友学人，早川慎二郎，圓山裕;K. Kitazono and K. Sekido
Zn-22 Al共晶合金是一种典型的超塑性材料，其高温延伸率超过500%。采用常规铸造工艺成功制备了Zn-22 Al超塑性泡沫合金。发泡温度约为750 K，低于常规泡沫铝。泡沫Zn-22 Al合金的孔隙率在50 ~ 80%之间。固溶处理后，细胞壁由细小的等轴晶粒组成。通过高温拉伸和压缩试验研究了泡沫Zn-22 Al合金的高温变形行为。Zn-22 Al泡沫合金具有较高的应变速率敏感性（0.55），这是由于泡沫材料的超塑性变形所致。用局部应变速率这一新参数解释了高温变形机制。与泡沫铝相比，Zn-22 Al泡沫铝具有较高的高温塑性。这是由于胞壁中的微细结构引起的超塑性变形所致。此外，大多数超塑性材料由于其晶界滑动而具有优异的阻尼性能。泡沫Zn-22 Al材料是一种有应用前景的减震或阻尼材料。
Zn-22Al eutectic alloy is a typical superplastic material which exhibits over 500% elongation at high temperature. Superplastic Zn-22Al alloy foams were successfully manufactured through a conventional casting process. Foaming temperature was about 750 K which was lower than that of conventional aluminum foams. The porosity of Zn-22Al alloy foams is between 50 and 80%. The cell wall consisted of fine equiaxial crystal grains after solution treatment. High temperature deformation behavior of Zn- 22Al alloy foams was evaluated through tensile and compressive tests at high temperature. Zn-22Al alloy foams exhibited high strain rate sensitivity of 0.55, which was caused by superplastic deformation of the cell wall material. High temperature deformation mechanism can be explained using the new parameter of local strain rate. The Zn-22Al foams showed relatively high ductility at high temperature compered to aluminum foams. This is because of the superplastic deformation induced by the fine microstructure in the cell wall. In addition, most superplastic materials have excellent damping property due to their grain boundary sliding. Present Zn-22Al foams are applicable as either shock absorbing or damping material in the future.