Abstract：A Ti-46Al-2Cr-2Nb alloy ingot was prepared by the process of double vacuum arc melting. The composition distribution and microsegregation in Ti-46Al-2Cr-2Nb alloy were studied. The microstructure and phase composition of the alloy were investigated by means of back scattered electron imaging, X-ray diffraction, energy dispersive spectrometry, and chemical composition analysis. The main results in detail are as follows：In the transverse sections, the content of Al is at the highest level in the place of R/2, however, the content of Al is low on the edge and radial zone of the ingot. The content of Cr is increased and the content of Nb is gradually decreased from the fringe to the center of the ingot, respectively. Along the longitudinal sections, the content of Al is gradually decreased from the bottom to the top of the ingot, the distribution of Cr is following the law of positive segregation elements, and the segregation law of Nb is similar to that of the Al element. The microstructure of the ingot mainly consists of α2 and γ phases. Most areas of the ingot are composed of α2+γ lamellar groups and a small amount of equiaxed γ phases at the colony boundaries, what is called nearly fully lamellar. The areas in the centre of the upper part ingot have a full lamellar structure composed of α2+γ phase. The microsegregation of the ingot exists around colony boundaries, where the microsegregation of Cr element is quite serious.
李晓磊;李金山;钟宏;寇宏超;张铁邦;常辉. VAR熔炼TiAl铸锭的成分分布及显微偏析[J]. , 2012, 30(6): 24-29.
LI Xiaolei;LI Jinshan;ZHONG Hong;KOU Hongchao;ZHANG Tiebang;CHANG Hui. Composition Distribution and Microsegregation in TiAl Ingot by Using VAR Process. , 2012, 30(6): 24-29.