Transactions of Nonferrous Metals Society of China
JOURNAL OF RAILWAY SCIENCE AND ENGINEERING
|Vol. 5 No. 1 March 1995|
（Analytical and Testing Center; Southeast University; Manjing 210018）
Abstract:The morphology , composition and crystal structure of the precipitation in a Cu-Zn-Al-Mn-Ni-Ti shape memory alloy have been studied. The results indicated that there were two different second phase particles in the as-quenched microstructure : a large irregular-shaped XL phase and a fine dispersed XS phase, both of which were ordered L21 b. c. c. structure with the composition(CuNiFe)2 TiAl. For the case of XS, the lattice parameter a(XS)=0. 5879 nm. With low solution-treatment temperature and short treatment time, the XS phase was fine dispersed and coherent to the matrix , nevertheless , the coherency would be destroyed by the growth of XS phase as treatment temperature and time increasing.
Key words: crystal structure; shape memory; second phase