Effects of processing parameters on the surface quality of directionally solidified tita-nium alloy slab with cold crucible

Titanium and TiAl-based alloys are promising structurematerials for aero/space-crafts of next generations due totheir excellent properties, such as high specific strength,high specific rigidity, high oxidization resistance and highcreep resistance at high temperature[1-3]. However, the Tialloys are highly active, especially in molten state they canreact with almost all other materials. This makes thespontaneous nucleation difficult during solidification andresults in coarse structures. These …

Effects of processing parameters on the surface quality of directionally solidified titanium alloy slab with cold crucible

Experiments of continuous and directional solidification of titanium alloy slabs were performed using authors-designed multi-function directional solidification apparatus with rectangular cold crucible. Influences of processing parameters on the surface qualities of the solidified slabs were studied. It is shown that the slab surface qualities can be effectively improved with increasing of the turns in coil and input power, and with decreasing of withdrawal velocity and relatively low position of pedestal to the induction coil. The influences of the processing parameters in the descending order are as follows: the turns in coil, input power, withdrawal velocity and the relative position of pedestal. With optimized parameters, quality slabs free from cracks and ripples were obtained. The solidified structure with good surface quality shows directionally solidified structure.