Temperature distribution for controlled-dwell extrusion of γ-TiAl
来源期刊：中南大学学报(英文版)2005年第3期
论文作者：刘冬 柏春光 崔玉友 杨锐
文章页码：276 - 279
Key words：TiAl alloy; controlled-dwell extrusion; can; temperature gradient
Abstract: Ti-47Al-2Cr-2Nb-0.15B alloy (atom fraction) was extruded at temperatures(Tα) of 1 250 and 1 330℃,respectively. The method of adding a thermal insulating layer was used to overcome the problem associated with the flow stress mismatch between the can and the billet during extrusion. Effects of two kinds of insulations, ZrO2 powders and silica fibers, on the quality of extrude bar along the radial direction were studied, and the process parameters were optimized by combining with finite element method (FEM). Tensile properties of the extruded alloy at room and elevated temperature were tested. The results show that the silica fibers has better thermal insulating property than ZrO2 powders. The temperature distribution in radial is more homogeneous using silica fibers. The alloy has a good balance of yield strength and room temperature ductility and the values are 680 MPa and 3.5%, respectively.
