材料非均匀性对泡沫金属拉伸性能的影响

通过对开孔泡沫铝进行拉伸实验,考察了泡沫金属材料的非均匀性对其拉伸性能的影响.首护先,通过分析同一批试件的初始密度,考察了材料的初始非均匀性;其次,重点考察了初始密度对材料破坏特性的影响.分析表明,即使初始密度比较接近的试件,它们的破坏应力和应变也有较大的离散性;对于不同初始密度的试件,破坏强度有随初始密度的增加而变大...

Effects of Material Heterogeneity on the Tensile Properties of Metal Foams

Experimental investigation of material heterogeneity effect on the tensile properties of metal foam was carried out. Firstly, the material initial heterogeneity was reviewed by analyzing the initial density of specimens of the same group. Next, the review was focused on the effect of initial density on the material failure characteristic. Analytical results show that even for specimens with approximate same initial density, their failure stress and strain still present obvious discreteness. And for the specimens with different initial density, their failure stresses increases with the increment of initial density, but failure strain does not present any obvious regular patterns. Therefore, for metal foam with highly complicated meso-structure heterogeneity, it is not enough to describe their material characteristics only using initial density. Image analysis of the foam aluminum tensile failure characteristics shows that the material failure is caused by the meso- structure's failure appeared at the tensile later stage, which indicates that the nonlinearity at the early tensile stage is mainly caused by the yield of matrix material induced due to the serious heterogeneous meso-structure.