中文摘要：

主要研究了具有不同孔隙梯度分布的多孔Mg-Ca合金在横向和纵向压缩时孔洞的受力以及变形特征,分析了梯度多孔Mg-Ca合金在弯曲时裂纹扩展机理,并观察了孔隙梯度结构和烧结温度对梯度多孔Mg-Ca合金力学性能的影响。研究结果表明,梯度多孔Mg-Ca合金的力学性能优于均匀多孔材料,随着试样边缘和中心孔隙度差距的增加,试样的抗弯强度、抗压强度和弹性模量均增加,纵向压缩时样品抗压强度和弹性模量的增加优于横向压缩,这主要归因于孔隙的梯度分布导致受力时外加载荷的重新分配。随着烧结温度增加,梯度多孔Mg-Ca合金的力学性能增加,在620℃烧结2h时力学性能达到最佳。

英文摘要：

In this paper suffered load modes and deformation characteristics of pores were studied at landscape and portrait orientation compression for porous Mg-Ca alloys with different gradient pore distribution.Expansion mechanism of bending crack of gradient porous Mg-Ca alloys was analyzed.Effects of pore gradient structure and sintering temperature on mechanical properties were observed.The results show the mechanical properties of gradient porous Mg-Ca alloys are prior to those of uniform porous samples.With the increase of pore gradient distribution,the bending strength,compressive strength,Young＇s modulus all increase.The improvement of compressive strength and Young＇s modulus after portrait orientation compression are higher than those after landscape orientation compression because the gradient distribution of pores can result in anew assignment of additional loads.With the increasing of sintering temperature,the mechanical properties of gradient porous Mg-Ca alloys increase.When sinter at 620℃ for 2h,the mechanical properties of gradient porous Mg-Ca alloys come to the maximum.