Effect of minor Fe addition on glass forming ability and mechanical properties of Zr55Al10Ni5Cu30 bulk metallic glass

A series of rod samples with diameter of 3 mm (Zr0.55Al0.10Ni0.05Cu0.30)100-xFex(x=0, 1, 2, 3, 4) were prepared by magnetic suspend melting and copper mold suction casting method. The effects of a small amount of Fe on glass forming ability(GFA) and mechanical properties of Zr55Al10Ni5Cu30 bulk metallic glass (BMG) were investigated. The results show that the addition of an appropriate amount (less than 3%, mole fraction) of Fe enhances GFA, as indicated by the increase in the reduced glass transition temperature Trg(=Tg/Tl) and the parameter γ(=Tx/(Tg+Tl)) with increasing Fe content, and GFA gets deteriorated by further Fe addition (4%). The addition of Fe also effectively improves the compressive plasticity and increases the compressive fracture strength in these Zr-based BMGs. Compressive tests on BMG sample with 3 mm in diameter and 6 mm in length reveal work-hardening and a certain plastic strain in the alloy containing 2% Fe. The BMG composite containing 4% Fe also exhibits a high fracture strength along with significant plasticity.