不同温度下泡沫铝压缩行为与变形机制探讨

利用Hopkinson杆与MTS实验装置分别研究泡沫铝在不同温度下的动态与静态力学性能，实验结果表明，泡沫铝有很强的温度软化效应，坍塌应力与平台应力和“应力降”的大小均随温度的升高而降低。动态高温下应力应变曲线与静态低温下应力应变曲线类似，反映材料应变率与温度之间的等效关系。低温下泡沫金属强度较高，脆性较强，泡沫结构易脆性坍塌，并伴有脆性裂纹，随着温度的升高，基体材料逐渐软化，泡沫金属强度降低，胞孔结构在压缩过程中从低温下脆性失稳逐渐变成以胞壁屈曲与塑性变形为主，且在不同温度段，应变率敏感度不同。

Compressive behavior and deformation mechanism of aluminum foam under different temperature

Using the Hopkinson bar and MTS devices to study the dynamic and quasi-static compression behavior in different temperature conditions. The compressive stress strain curve of the Aluminum foam was found to be strongly temperature dependent. It is obvious that the curve under high temperatures was close to that under low temperatures and exhibited a consistent relationship of time-temperature equivalent. At low temperatures the matrix material reveals more brittle characteristic and causes the cell structures to collapse abruptly, and results in a notable “stress drop” and remarkable vibration. But when raising the ambient temperature, the material tends to exhibit ductile property, and deformation of cell structure is mainly through plasticity buckling instead of abrupt collapse.