开孔泡沫铝压坑力学行为研究

分别采用头部为平面、球面和圆锥面的三种圆柱体压头,对泡沫纯铝和泡沫铝-硅合金进行了准静态压坑试验,研究不同性质的基体泡沫铝的压坑变形力学行为,探讨压坑变形的微观机制。结果表明:不同形状压头的压坑载荷-位移响应特征均与单轴压缩的响应相比均有较大差别,其显著特征是随着变形量的增大应力上升的速度较快,泡沫铝的压坑载荷-位移曲线的形状还与所用压头的形状密切相关;随着泡沫铝基体性质的不同,其压坑变形宏观形态和微观机制也存在较大的差异。

Investigation on indentation deformation mechanical behavior of open-cell aluminum foams

The quasi-static indentation experiments of the pure aluminum foams and the Al-Si alloy foams were carried on using three types of indenter with different end geometries,i.e.flat-ended punch(FEP),spherical-ended punch(SEP) and conical-ended punch(CEP),respectively.Indentation deformation mechanical behavior of open-cell aluminum foams with different matrixes was investigated.And the deformation mechanism of the foams was discussed.The results show that the indentation load-displacement response of the foams is much different from that under quasi-static uniaxial compressive.The distinct character of the response is that the stress increases as deformation increasing rapidly.Moreover,the shape of the indentation load-displacement curves of the foam closely depends on the shape of the indenters.Otherwise,as the foams have different matrixes,the indentation macroscopic deformation modality and the indentation microcosmic deformation mechanism of the foams have great difference.