Zr_(55)Cu_(30)Al_(10)Ni_(5)块体金属玻璃的成分优化设计及其晶化行为

Optimization Design of a Bulk Metallic Glass Zr_(55)Cu_(30)Al_(10)Ni_(5)and its Crystallization Behavior

参照Zr_(55)Cu_(30)Al_(10)Ni_(5)合金的成分并应用团簇加连接原子模型,设计具有高玻璃形成能力的Zr-Cu-Al-Ni体系成分。在Zr-Cu-Al-Ni四元体系中,先定出两个与金属玻璃形成相关的晶化相CuZr_(2)和CuZr,其中的局域结构可分别用团簇表述为[Cu-Zr_(8)Cu_(4)]和[Cu-Zr_(8)Cu_(6)],然后应用双团簇模型将这两个团簇按照1∶1的配比构建双团簇式,连接原子个数为2或4或6,由此确定总原子个数为30或32或34,进而选择双团簇式原子总数为32设计出最接近Zr_(55)Cu_(30)Al_(10)Ni_(5)合金的四元块体金属玻璃成分Zr1_(7)Cu_(10)Al_(3)Ni_(2)≈Zr_(53.1)Cu_(31.3)Al_(9.4)Ni_(6.3)。这种合金玻璃的Trg值可达0.6,晶化激活能为334.138 kJ/mol,均略高于参照合金Zr_(55)Cu_(30)Al_(10)Ni_(5),表明其具有更高的玻璃形成能力。

According to the principle of cluster-plus-glue-atom model,the composition of a novel Zr-Cu-Al-Ni alloy with glass formation ability was designed by taking the alloy Zr_(55)Cu_(30)Al_(10)Ni_(5)as reference.In the quaternary Zr-Cu-Al-Ni system,two crystallization phases CuZr_(2)and CuZr related with amorphous formation were firstly identified,the local structures of these two clusters can be expressed as[Cu-Zr_(8)Cu_(4)]and[Cu-Zr_(8)Cu_(6)]respectively;then,by combining these two clusters in equal proportion while coupling with the number of glue atoms 2,4,or 6,the dual-cluster formulas for total atom number of 30,32,or 34 respectively may be constructed by means of the dual-cluster model.Furthermore,according to dualcluster formula of the total number of atoms of 32,a quaternary alloy with composition Zr_(17)Cu_(10)Al_(3)Ni_(2)≈Zr_(53.1)Cu_(31.3)Al_(9.4)Ni_(6.3)was tentatively designed,which is closest to the reference Zr_(55)Cu_(30)Al_(10)Ni_(5).The glass formation ability of this alloy was tested experimentally.The results show that its Trg reaches 0.6 and its crystallization activation energy is 334.138 kJ/mol,which are all slightly higher than that of the reference alloy,indicating that the designed alloy has a higher glass formation ability.