原位晶态相增强Mg-Cu-Dy非晶基块状复合材料

In-situ Mg Phase Reinforced Mg-Cu-Dy Bulk Metallic Glass Matrix Composites

摘要:

采用铜模喷铸法制备出直径为3 mm的原位Mg晶态相增强块状Mg70Cu17Dy13非晶基复合材料，对Mg-Cu-Dy类合金的力学性能和变形行为进行研究。结果表明，Mg70Cu17Dy13非晶基复合材料受压时产生加工硬化并获得最大抗压强度为702.38 MPa和塑性变形率为0.81%。这缘于其中Mg相有效的承载能力、塑性变形能力及Mg相对剪切带及裂纹扩展的有效抑制作用，可从其剪切变形、断裂方式和断裂面上密集的熔滴及凸凹不平得到证实

Abstract:

In-situ Mg phase reinforced Mg70Cu17Dy13 bulk metallic glass (BMG) matrix composite with diameter of 3 mm was prepared by a conventional Cu-mold casting method. Mechanical properties and deformation behavior of Mg-Cu-Dy alloys were studied. The results show that the Mg70Cu17Dy13 BMG matrix composite exhibits some work hardening except for initial elastic deformation, and achieves a high fracture compressive strength of 702.38 MPa and a plastic strain of 0.81%. The improvement of the mechanical properties is attributed to the fact that the Mg phase distributed in the amorphous matrix of the alloy has effective load bearing and plastic deformation ability to restrict the expanding of shear bands and cracks and produce its own plastic deformation, which is proved by the shear deforming and fracturing mode and the fracture surfaces characterized by the vein patterns, severe remelting and the very rough and bumpy region of the alloy