New icosahedral quasicrystals formed in Cu-based ternary alloys
New icosahedral quasicrystals formed in Cu-based ternary alloys
复制标题
DOI：
10.1080/14786430701361339
复制
发表时间：
2007-01
影响因子：
1.6
通讯作者：
T. Honma;T. Ishimasa
中科院分区：
文献类型：
--
作者：
T. Honma;T. Ishimasa
在Cu-(Ga或Al)-Sc三元合金系中观察到了新的铜基P型二十面体准晶。Cu-Ga-Sc准晶几乎完全形成于快冷Cu48Ga34Sc18合金中，具有六维晶格参数a 6D=0.6930 nm。相同成分的铸态合金不含准晶，主相为1/1的体心立方相。在铸态合金和773K和873K时效合金中，Cu-Al-Sc准晶均在合金成分Cu46Al38Sc16处形成，晶胞参数为a_6D=0.6959 nm。尽管电子衍射图与弱反射的理想对称位置有较大偏离，但时效后的Cu-Al-Sc合金中有准晶的存在，表明该相是该三元系中稳定相的候选相。
New Cu-based P-type icosahedral quasicrystals have been observed in the ternary Cu–(Ga or Al)–Sc alloy systems. The Cu–Ga–Sc quasicrystal forms almost exclusively in a rapidly quenched Cu48Ga34Sc18 alloy, and has a six-dimensional lattice parameter a 6D = 0.6930 nm. The as-cast alloy with the same composition contains no quasicrystal but has a 1/1 bcc approximant as its main phase. The Cu–Al–Sc quasicrystal forms at the alloy composition Cu46Al38Sc16 both in an as-cast alloy and in alloys aged at 776 and 873 K, and has a lattice parameter a 6D = 0.6959 nm. Although electron diffraction patterns exhibit rather strong deviation from the ideal symmetric positions for weak reflections, the presence of the quasicrystal in the aged Cu–Al–Sc alloys indicates that this phase is a candidate of a stable phase in this ternary system.