【摘要】 利用变电子浓度经验判据,从Cu-Zr亚组元体系中的最深共晶点Cu61.8Zr38.2和次深共晶点Cu56Zr44出发,连接第三组元Al,建立(Cu81.8Zr38.2)1-xAlx和(Cu56Zr44)1-xAlx变电子浓度线.电子浓度在1.24—1.30的(Cu61.8Zr38.2)1-xAlx合金可通过铜模吸铸法形成直径为3 mm的块体非晶;对于(Cu56Zr44)1xAlx系列合金,块体非晶形成的电子浓度区间为1.28—1.36.热分析结果表明,每条变电子浓度线上块体非晶合金的热稳定性和玻璃形成能力随电子浓度增大而增加.其中, (Cu61.8Zr38.2)1-xAlx变电子浓度线上的非晶合金Cu58.1Zr35.9A16(e/a=1.3)具有最高的热稳定性和最大的玻璃形成能力,其特征参数Tg=760 K,Tg/Ti=0.648,皆高于已报道的最优成分Cu55Zr40Al5(Tg=722 K,Tg/Ti=0.614).更多还原

【Abstract】 The composition optimization of the Cu-based Cu-Zr-Al bulk metallic glasses (BMGs) has been realized by using the e/a-variant criterion. This criterion is incarnated by two composition lines, (Cu61.8Zr3832)1-xAlx and (Cu56Zr44)1-xAlx, which are defined by linking the deepest eutectic point Cu61.8Zr38.2 and sub-deepest eutectic point Cu56Zr44 in Cu-Zr sub-system with the third element Al, respectively. BMGs of 3 mm in diameter have been obtained by means of copper mould suction casting within e/a spans from 1.24 to 1.30 along (Cu61.8Zr38 2)1-xAlx line and from 1.28 to 1.36 along (Cu56Zr44)1-xAlx line. Thermal analysis indicates that the BMGs on every composition line manifest increased thermal stability and glass forming ability (GFA) versus increasing e/a ratios. The maximum appears in Cu58.1Zr35.9Al6 with the upper e/a limit of 1.3 on the (Cu61.8Zr38.2)1-xAlx composition line. The characteristic thermal parameters of this BMG are Tg = 760 K, Tg/T1 = 0.648, which are all superior to those of the reported reference BMG Cu55Zr40Al5 (Tg = 722 K, Tg/T1 = 0.614).更多还原