Fabrication And Study Of Mechanical Performance Of Magnesium-base Amorphous And Magnesium Matrix Composites Material

The AZ91 magnesium alloy foam with a diameter of 9mm were fabricated by using vacuum melt infiltration and water quenching methods. NaCl salt was used as a placeholder in this investigation. The porosity and density were 0.602 and 0.724 g/cm³ respectively for the AZ91 magnesium foam. The pores were evenly distributed in the material. The plastic strain during compression for the AZ91 magnesium alloy foam is much higher than that of the as-cast AZ91 magnesium alloy fabricated by the same process. The fracture event occurred at low stress during the pores vanishing, which is the first evidence observed in metal foam materials during compression according to our knowledge.The AZ91 magnesium based composites reinforced by wire and steel web have been fabricated by melt infiltrating casting method. The volume fraction of wire and steel web are different. An optical microscopy and a scanning electronic microscopy were used to investigate the structure of the composite and the microscopic morphologies of the fracture surface. The compression results show that the yielding strength of the composites is higher than that of the AZ91 magnesium alloy,and the extent is increased with increase of the volume fraction of wire and steel web. In the same time, the volume fraction of wire and steel web also has large effect on the fracture modes of the composites.we studied the glass-forming ability of the Mg-Cu-Nd alloy system. It was found that three alloy could be cast into amorphous rods with a diameter of 3mm. The high and obvious observable glass transition temperature(Mg₅₅Cu₃₅Nd₁₁) T_g(419K), remarkable supercooled liquid regionâ–³T_x=T_x-T_g(53K) of the amorphous rods, suggest that such a alloy is a good glass former and with high thermal stability. The fracture of Mg₅₃Cu₃₇Nd₁₀ alloy strengthσ_f at room temperature is 685MPa.Mg-Ni-Zn-Y alloys were prepared by copper mold casting. The microstructure and the mechanical properties of the alloys have been investigated. The results indicate that the compressive fracture strength of alloys is as high as 433MPa.