铸态Ti-Zr-(Ni,Co)伪三元准晶合金研究

Investigation on As-cast Quasicrystalline Alloys in the Ti-Zr-(Ni,Co) Pseudo-ternary System

沿Ti9(Ni,Co) 4 Zr变电子浓度线设计系列合金成分,用吸铸方法可制备出Ti Zr (Ni,Co)准晶,其中Ti4 2 Zr4 0 (Ni,Co) 1 8为形成准晶的最佳成分点,Ti Zr (Ni,Co)伪三元准晶系列的准点阵常数介于0 5 0 6～0 5 18nm之间。实验结果表明,Co是形成准晶的不利组元,其含量的增加将促使Ti2 Ni、fcc Zr2 Ni和βZr(Ti)固溶相的形成,使合金中准晶相的含量大为降低;但适量Si的加入(～2at% )能促进Ti Zr (Ni,Co)准晶的形成。

In a series of alloys along a Ti9(Ni, Co)4-Zr e/a-variant line prepared by suction casting, icosahedral quasicrystals were obtained with quasilattice constant 0.506-0.518 nm. Experimental results show that in the Ti-Zr-(Ni, Co) pseudo-ternary system, the Ti42Zr40 (Ni, Co)18 alloy is optimal for quasicrystal formation, and increasing Co content contributes to the formation of Ti2Ni, fcc-Zr2Ni and β-Zr (Ti) phases, and greatly decreases the fractions of quasicrystals in the alloys, suggesting that Co is unfavorable for Ti-Zr-(Ni, Co) quasicrystal formation. However, the addition of 2 at% Si significantly improves the quasicrystal-forming ability.