泡沫铝结构对其拉伸力学性能的影响

Effect of Cell Structure on the Uniaxial Tensile Properties of Aluminum Foams

研究了开孔与闭孔两种胞孔结构的泡沫铝在不同相对密度下的准静态拉伸力学性能,并与单向压缩性能进行了对比。结果表明：开孔和闭孔泡沫铝的拉伸曲线由线弹性变形段和塑性变形段组成,线弹性变形段很短,塑性屈服中没有出现明显的屈服点；高密度的开孔泡沫铝的杨氏模量、抗拉强度较低密度的闭孔泡沫铝要大；随着相对密度的增大,两种结构泡沫铝的力学性能均明显增强,符合Gibson和Ashby关系式,泡沫铝在准静态下的抗拉强度比抗压强度略低,而拉伸杨氏模量比压缩杨氏模量大得多。

The uniaxial tensile properties of two aluminum foams （open-cell and closed-cell foams） with a variety of densities were studied and compressive tests were carried out. The tensile stress-strain curves of open cells and closed cells all showed short elastic deforming region and plastic region without apparent plastic point. Young＇s modulus and strength of open cells with high density were higher than those of closed cells. The mechanical properties increased with increasing relative density of foams. The tensile strength was lower than compressive strength, however, Young＇s modulus was larger in tension than in compression.