Thermal Stability of Zr_(50)Ti_5Cu_(18)Ni_(17)Al_(10) Bulk Amorphous Alloy
Bulk amorphous alloy Zr50Ti5Cu18Ni17Al10 was prepared by copper mold suck-casting method,and the thermal stability was investigated by use of differential scanning calorimeter(DSC) and X-ray diffractometer(XRD).The glass transition temperature(Tg),the crystallization onset temperature(Tx) and peak temperatures(Tp) shift to the high temperature region with the increase of heating rate,indicating the glass transition and crystallization are kinetic processes.The activation energies of glass transition(Eg) and crystallization(Ep1 and Ep2) are 438±11、 284±8 and 323±11 kJ/mol,respectively,calculated by Kissinger method.The crystallization of the amorphous alloy is divided into three processes: the precipitation of the nanocrystals,the primary phase(ZrAl,ZrCu and Zr2Ni) and the stable phase(Zr2Cu,Zr2Ni,ZrCu,ZrAl and an unkown phase).