Evol ution ofPhase Tran sformatio n in Nan ocrystallin e/Amorp hous Ti-۴ ۱Ni-۹Cu Shape M emory Alloys Synt hesized by Ball Milling

In co mparison to binary Ni Tishape memory alloy s (SMAs), TiNiCu all oys exhibit more favorable properties such as small transformation hy steresis and higher corrosion resis tance.Accordingly, these smart materials are widely used in differen t fields like electronics and medical applications [۱].In the present work, phase trans formation of the alloying system during the milling processwasinves tigated. Exper imental Procedure:High purity eleme ntal titaniu m, nickel and copper po wders were mixed wit h the atomic ratio of ۵۰:۴۱:۹ and the n mechanically alloyed in a planetary ball mill under argon atmosphere . The milling was performed at roo m temperatu re with the speed of ۴۵۰ rpm and t he ball-to-po wder massratio of ۲۰:۱. The phase constituent and structur al properties of the powders were studied by po wder X-ray diffraction (XRD, Pananalytical, X'pert Pro MP D) with the CuKa (λ= ۰.۱۵۴ nm) r adiations. T he quantitat ive analyses were done according to previous work [۲].Then, to investigate the microstructur al features of the as-milled powders, selected powder par ticles were characterized by a high-resolution transmissi on electron microscope (HRTEM, FEI,Tecnai G۲ F۳۰).

کلیدواژه ها:

TiNiCu shape me mory alloys ، mechanical alloying ، phase transformation