Mechanical Properties and Microstructures of Composites of Ti-Based Metallic Glass and β–Ti

Abstract

Microstructures and mechanical properties of Cu mold-cast Ti₅₀Cu₂₅Ni₁₅Sn₅Ta₅ and Ti₄₅Zr₅Cu₄₄Ni₅Ta₁ alloys were investigated by means of X-ray diffraction, electron microscopy and compressive testing. Ti₅₀Cu₂₅Ni₁₅Sn₅Ta₅ alloys form microscopic composites consisting of Ti-based metallic glass as primary phase and β–Ti phases, while Ti₄₅Zr₅Cu₄₄Ni₅Ta₁ alloys consisting of Ti-based metallic glass matrix and high density of nanocrystals dispersed in the matrix homogeneously. Ti₅₀Cu₂₅Ni₁₅Sn₅Ta₅ bulk composite alloys showed 1.6% of plastic deformation and 2200 MPa of 0.2% of proof stress. The alloys also exhibited work hardening because of the presence of microscopic crystalline phases. Ti₄₅Zr₅Cu₄₄Ni₅Ta₁ bulk alloys also deformed plastically after stress reached 2000 MPa without work hardening.