Mechanical alloyed Ti-Cu-Ni-Si-B amorphous alloys with significant supercooled liquid region

摘要

This study examined the glass formation range of Ti_(94-x-y)Cu_xNi_ySi_4B_2 alloy powders synthesized by mechanical alloying technique. According to the results, after 5-7 h of milling, the mechanically alloyed powders were amorphous at compositions with (x+y) equal to 20-40 percent. For the compositions with (x+y) larger than 45 percent or smaller than 10 percent, the structure of ball-milled powders is a partial amorphous single phase or coexistent partial amorphous and crystalline phases, respectively. The thermal stability of the amorphous powders was also investigated by differential thermal analysis. As the results demonstrated, several amorphous powders were found to exhibit a wide supercooled liquid region before crystallization. The temperature interval of the supercooled liquid region defined by the difference between T_g and T_x, i.e. DELTA T(=T_x-T_g), are 52 K for Ti_(74)Ni_(20)Si_4B_2, 74 K for Ti_(64)Ni_(30)Si_4B_2, 58 K for Ti_(64)Cu_(20)Ni_(10)Si_4B_2, and 61 K for Ti_(74)Cu_(10)Ni_(10)Si_4B_2.