Deformation Behavior Of Ti/Mg-based Metallic Glass Interpenetrating Phase Composite

Mg-based bulk metallic glass has excellent properties of low density, high specific strength and specific stiffness, which has attracted more and more attention. However, Mg-based bulk metallic glass shows very little macroscopic plastic deformation and breaks into pieces catastrophically before yielding. A comprehensive performance of the Ti/Mg-based metallic glass interpenetrating phase composite was successfully fabricated to solve this problem. Thus, this paper is to systematically investigate the mechanical properties and deformation behavior of pure Mg-based amorphous alloy and composite with different porosity under different strain rates and temperatures. The major results are as follows:For the monolithic Mg61Cu20.3Ag8.7Er10amorphous alloy, its fracture strength decreases as the strain rate increases at room temperature. When the temperature is-100℃, the amorphous alloy exhibits high strength together with slight plasticity. The strain rates take little effects on the strength and plasticity at this time.Using pressure infiltrating method, we successfully prepared Ti/Mg-based metallic glass interpenetrating phase composites with two porosities of40%and60%. Both composites fail in the shear mode. The composite with40%porosity has better quasi-static mechanical properties, whose yield strength σ y, fracture strength σ f and plastic strain ε p is925MPa,1027MPa and13.5%, respectively. Its yield strength and fracture strength increase with increasing strain rate when the strain rate varies from10-4s-1to10-1s-1, and the shear angle changes from30°to45°. Under the condition of dynamic compression, the fracture strength significantly increases to1260MPa when strain rate is at the level of103s-1.When the strain rate fixes at5×10-4s-1, the composite with60%porosity has highest fracture strength at-100℃, without any plasticity. When the temperature lies in the super-cooled liquid region of amorphous alloy, the yield strength drops from605MPa to461MPa, the fracture strength from740MPa to620MPa, respectively, and the total strain increases from20%to30%. When the strain rate increases from5×10-4s-1to1×10-1s-1, the room temperature strength of the composite is stable of about 920MPa. During-100℃, both yield and fracture strength increase as the strain rate increases. The stress presents sudden drops during the deformation at180℃.