Effect of continuous equal channel angular pressing on microstructure and properties of Al-Ti-C alloy

Abstract

The Al-Ti-C alloy was extruded in multiple passes in a continuous manner by continuous equal channel angular pressing process. Through observation of the microstructure evolution, the mechanism of grain refinement and changes in mechanical properties were discussed.The results show that continuous equal channel angular pressing process can effectively refine the microstructure of Al-Ti-C alloy, and the grain size is reduced to about 1 μm.The deformation induction is the most important grain refinement mechanism in the deformation process.The accumulation of high density dislocations causes cracks at the interface between the Al matrix and TiAl3 and voids inside the TiAl3. The cracks further propagate through the entire TiAl3 particles, ultimately leading to the refinement of the second phase TiAl3 structure.At the same time, the pinning mechanism and shearing mechanism of the fine second phase TiAl3 structure promote the refinement of the Al matrix.After one pass of continuous equal channel angular pressing, the hardness of the alloy increases most obviously, which is 59.2% higher than that of the original state.With the increase of the number of extrusion passes, the increasing trend of hardness slows down, the plasticity of the alloy decreases, and toughness increases.

Keywords

• continuous equal channel angular pressing
• al-5ti-0.2c alloy
• refinement mechanism
• tial3