Effect of carbon addition on the thermal stability and glass forming ability of Misch metal-based bulk metallic glass matrix composites

摘要

The effect of carbon addition on the glass forming ability (GFA) and thermal stability in the Misch metal (Mm) based alloys with compositions of (Mm_(0.55)Al_(0.25)Ni_(0.1)Cu_(0.1))_(100-x)C_x(x=0-8 at%) have been systemically investigated. For the as-cast alloy ingot (x=7 at%) with a cross sectional diameter of 10 mm, the microstructure was consisted of μm-sized crystalline phases uniformly distributed in the metallic glass matrix. The addition of a carbon is effective in increasing the thermal stability of the metallic glass and GFA, presumably because of the generation of attractive bonding with Lanthanide elements, leading to the suppression of formation of the competing crystalline phases. The bulk metallic glass matrix composite (x=4 at%) exhibits enhanced compressive fracture strength of 1.08 GPa with a room-temperature plasticity.