Effect Of Element Replacement Ni On Thermal Stability And Mechanical Properties Of ZrCuAlNiTi Amorphous Alloy

ZrCuAlNiTi amorphous alloy has glass forming ability,excellent mechanical properties and physical and chemical properties,and has broad application prospects,especially as a medicall material,has obvious advantages.However,nickel in the alloy system has side effects on human body.Therefore,the development of Zr based amorphous alloys without nickel have been the focus of research.Based on Zr₅₅Cu₃₀Al₁₀Ni₄Ti amorphous alloy,Ag,Hf,Fe and Sn were added in this paper,and the Ni element in Zr₅₅Cu₃₀Al₁₀Ni₄Ti amorphous alloy was gradually replaced.Zr₅₅Cu₃₀Al₁₀Ni₃TiAg,Zr₅₅Cu₃₀Al₁₀Ni₂TiAgHf,Zr₅₅Cu₃₀Al₁₀NiTiAgHfFe and Zr₅₅Cu₃₀Al₁₀TiAgHfFeSn alloy components were designed,and Zr base amorphous alloy round rods with different diameters were prepared by means of non-consumable arc furnace melting and copper die casting technology.The structures of four amorphous alloys were analyzed by X-ray diffraction?XRD?and transmission electron microscopy?TEM?.The amorphous forming ability and thermal stability of four amorphous alloys were studied by DSC analysis.The mechanical properties and fracture behavior of the amorphous alloy were analyzed by Instron universal material testing machine and scanning electron microscope?SEM?.The experimental results show that the glass forming ability and thermodynamic stability of the four amorphous alloy components were increase with the increase of element types.The critical dimensions of all four amorphous alloys reached 4mm.The critical diameter is larger than base amorphous alloy.Through DSC test and analysis at different heating rates,it was found that with the increase of heating rate,the heat release peak of DSC curve shifted to the right,and the characteristic thermophysical parameters of the four amorphous alloys showed a trend of moving to high temperature.The Kissinger formula and FWO formula were used to analyze and calculate the characteristic parameters of crystallization kinetics and the activation energy of crystallization.The results show that the activation energy of the characteristic temperature is higher than that of the basic amorphous alloy,indicating that the thermal stability of the alloy is enhanced.It was found that the vickers hardness of the four Zr based amorphous alloys decreased with the decrease of the atomic percentage of Ni.The change of compression strength has no obvious regularity.The compression strength of the component Zr55Cu30Al10Ni2TiAgHf amorphous alloy is the highest,up to 1912MPa,which is3.35%higher than that of the base Zr55Cu30Al10Ni4Ti amorphous alloy.For fracture analysis found that the compression fracture sample were less than 45°Angle along the direction of the shear fracture,the fracture behavior of room temperature shows a typical brittle fracture.