Ta,Nb和Mo对Ti_(50)Ni_(20)Cu_(25)Sn_5非晶合金玻璃形成能力的影响(英文)

Effects of Ta, Nb and Mo Additions on Glass-forming Ability of Ti_(50)Ni_(20)Cu_(25)Sn_5 Amorphous Alloy

利用旋转铜辊急冷法和铜模铸造法制备非晶合金薄带或圆棒,并采用X衍射仪(XRD)、差示扫描量热仪(DSC)和差示热分析仪(DTA)研究了Ta,Nb和Mo对Ti50Ni20Cu25Sn5非晶合金玻璃形成能力(GFA)的影响。结果表明,Ta的添加提高了Ti50Ni20Cu25Sn5合金的GFA,Mo的添加降低了该合金的GFA,Nb的添加则对该合金的GFA没有明显的影响;含Ta合金具有超过60K的宽过冷液态区(ΔTx),且其约化玻璃转变温度因子(Tg/Tm)大于含Nb合金和含Mo合金;采用常规铜模铸造法制备出了直径为1mm的(Ti0.5Ni0.2Cu0.25Sn0.05)98Ta2和(Ti0.5Ni0.2Cu0.25Sn0.05)96Ta4块状非晶圆棒;(Ti0.5Ni0.2Cu0.25Sn0.05)98Ta2块状非晶圆棒的Tg,ΔTx和Tg/Tm分别为678K,84K和0.60,而(Ti0.5Ni0.2Cu0.25Sn0.05)96Ta4块状非晶圆棒的Tg,ΔTx和Tg/Tm分别为680K,70K和0.60。

Effects of Ta, Nb and Mo additions on the glass forming ability (GFA) of the Ti50Ni20Cu25Sn5 alloy were studied by melt spinning and copper mold casting methods. X ray diffraction (XRD), differential scanning calorimetry (DSC) and differential thermal analysis (DTA). The results show that the GFA is improved by Ta additions and decreased by Mo additions. No obvious improvement is observed in Nb added alloys.The Ta added alloys exhibit a wide supercooled liquid region exceeding 60 K before crystallization. The reduced glass transition temperature (Tg/Tm) of the Ta added alloys is higher than those of the Nb and Mo added alloys. Cylindrical rods of 1 mm in diameter containing fully glassy phase were successfully synthesized for (Ti0.5Ni0.2Cu0.25Sn0.05)98Ta2 and (Ti0.5Ni0.2Cu0.25Sn0.05)96Ta4 by conventional copper mold casting. The Tg, ΔTx and Tg/Tm of the bulk glassy rod are 678 K, 84 K and 0.60 for (Ti0.5Ni0.2Cu0.25Sn0.05)98Ta2 alloy, and are 680 K, 70 K and 0.60 for (Ti0.5Ni0.2Cu0.25Sn0.05)96Ta4 alloy respectively.