Microalloying effect of Si on mechanical properties of Ti based bulk metallic glass

Abstract

The (Ti₄₀Zr₁₀Cu₃₆Pd₁₄)_{100 − x}Si_x (x = 0, 0·5, 1·0, 1·5) bulk metallic glass (BMG) rods with a diameter of 2–4 mm have been successfully fabricated by suction casting method and characterised. The X-ray diffraction results reveal that these entire (Ti₄₀Zr₁₀Cu₃₆Pd₁₄)_{100 − x}Si_x alloy rods exhibit a typical amorphous diffraction pattern with only a broad maximum at 2θ∼40°. The optimum glass forming ability values γ and γ_m (0·430 and 0·774 respectively) occur at the (Ti₄₀Zr₁₀Cu₃₆Pd₁₄)_99·5Si_0·5 amorphous alloy. This suggests that the Si element present a positive effect on increasing glass forming ability in the Ti₄₀Zr₁₀Cu₃₆Pd₁₄ alloy system. The hardness of these Ti based BMGs exhibits an increasing trend with Si addition and saturated ∼710 HV. In addition, the result of compression test shows that the optimum mechanical property occurs at the (Ti₄₀Zr₁₀Cu₃₆Pd₁₄)_99·5Si_0·5 amorphous alloy, which presents 2050 MPa fracture strength and 8% failure strain.

Keywords:

• Metallic glasses
• Mechanical properties at ambient temperature
• Casting
• Scanning and transmission electron microscopy