The structure of gamma-alpha(2) interfaces in deformed Ti-48Al-2Cr alloy was analyzed by high-resolution transmission electron microscopy (HREM) and image simulations. Growth of gamma-TiAl plate in alpha(2)-Ti3Al phase was found to be a result of a ledge mechanism consisting of Shockley partial dislocations on alternate (0001)(alpha 2) planes. The height of the ledges was always a multiple of two (0001)(alpha 2) planes. The gamma --> alpha(2) phase transformation was also an interface-related process. Large ledges of six close packed planes (111)(gamma) high were often observed at the gamma-alpha(2) interface. Every large ledge consisted of six Shockley partial dislocations that originated from the gamma-alpha(2) interfacial lattice misfit. The movement of these partial dislocations accomplished the transformation of gamma --> alpha(2) phase. Comparing the experimental and simulated HREM image, it was found that atomic reordering appears during the deformation-induced gamma <-> alpha(2) transformation.
部门归属
chinese acad sci, inst met res, atom imaging solids lab, shenyang 110015, peoples r china.;zhang, jx (reprint author), natl res inst met, subgrp 2, res grp 5, 1-2-1 sengen, tsukuba, ibaraki 3050047, japan
J. X. Zhang,H. Q. Ye. Deformation-induced alpha(2)<->gamma phase transformation in a Ti-48Al-2Cr alloy[J]. Journal of Materials Research,2000,15(10):2145-2150.
APA
J. X. Zhang,&H. Q. Ye.(2000).Deformation-induced alpha(2)<->gamma phase transformation in a Ti-48Al-2Cr alloy.Journal of Materials Research,15(10),2145-2150.
MLA
J. X. Zhang,et al."Deformation-induced alpha(2)<->gamma phase transformation in a Ti-48Al-2Cr alloy".Journal of Materials Research 15.10(2000):2145-2150.
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