Effects of Pd addition on the glass forming ability and crystallization behavior in the Ni-Zr-Ti alloys

摘要

The effect of Pd substitution for Ti on the glass forming ability and crystallization behavior has been studied in Ni_(57)Zr_(20)Ti_(23-x)Pd_x (x = 0, 3, 5, 7, 10) alloys. Partial substitution of Ti by Pd in Ni_(57)Zr_(20)Ti_(23-x)Pd_x improves the glass forming ability. With increasing Pd content x, from 0 to 7, ΔT_x and T_(rg) increase from 15 to 43 K and from 0.59 to 0.64, respectively. Crystallization sequence becomes completely different with addition of Pd. The amorphous Ni_(57)Zr_(20)Ti_(23) alloy crystallizes via precipitation of only cubic Ni(Ti,Zr) phase in the first crystallization step, whereas the amorphous Ni_(57)Zr_(20)Ti_(16)Pd_7 alloy crystallizes via simultaneous precipitation of orthorhombic Ni_(10)(Zr,Ti)_7 and cubic NiTi phase. Addition of Pd in the Ni_(57)Zr_(20)Ti_(23) alloy suppresses the formation of the primary cubic Ni(Ti,Zr) phase, leading to the improvement of glass forming ability.