最新色国产精品精品视频,中文字幕日韩一区二区不卡,亚洲有码转帖,夜夜躁日日躁狠狠久久av,中国凸偷窥xxxx自由视频

The microstructures of as-cast Ti-Al-Nb-W-B alloy were investigated to assess the possibility of eliminating the triaxial β(B2) phase on the crystal boundary through heat treatment and multi-step forging thermal mechanical treatment. The microstructure evolution and growth mechanism were studied according to Ti-Al-Nb ternary phase diagram, and then the process of eliminating of the triaxial β(B2) phase on the crystal boundary was assessed. The results of the experiments indicate that the best way to eliminate β(B2) phase is holding at the 1260 °C for 8 h or 1220 °C for 36 h followed by furnace cooling, but the grains grow appreciably. On the other hand, after multi-step forging with a total deformation of more than 80%, the as-cast nearly lamellar structure can be refined obviously to the duplex microstructure, and the β(B2) phase is basically eliminated.