Papers by Keyword: Al-Ti Alloy

Abstract: The Rotating Extrusion Alloying (REA) is a process which combined friction stir welding process and extrusion technology. In the REA process, dissimilar metals are mixed, cracked, and subjected to high speed, severe pressing deformation, and therefore rapidly alloy at a low temperature. The result shows that REA technology can be alloyed Al-Ti material. Its phases are mainly composed of Al and Al3Ti, which are distributed more evenly in the aluminum. After heat treatment, its phases’ types and pole figures have no significant change, but there is a trend of transition to the non-equilibrium stable phase. Small-angle grain boundaries decrease or even disappear.

Abstract: Porous Al-5mass%Ti alloys were fabricated using a continuous casting technique in a hydrogen atmosphere, and the effects of transfer velocity (V) and the peritectic solidification process on the pore morphology and matrix microstructure were examined. In the case of V = 0.5 mm/min, columnar microstructure and directional pores grow along the transfer direction. The Al3Ti phases are formed in localized regions of matrix part, and however, they do not suppress the growth of directional pores in the other regions. In the case of 5.0 mm/min, because needle-like Al3Ti phases grow along the transfer direction, directional pores can grow between them. On the other hand, in the case of 10.0 mm/min, spherical pores surrounded by equiaxed peritectic microstructure and homogeneously distributed Al3Ti phases are formed, because the primary α -Al and Al3Ti phases probably prevent the growth of directional pores.

Abstract: Al-Ti alloys, which have Al3Ti platelet particles in Al matrix, were deformed by ECAP with routes A and Bc. With increasing the number of ECAP passes, Al3Ti platelet particles are fragmented and their sizes decrease. The microstructure of ECAPed Al-Ti alloy specimens by route A has a strong alignment of the fragmented Al3Ti particles. On the other hand, ECAPed Al-Ti alloy specimens by route Bc have a relatively homogeneous distribution of Al3Ti particles comparing with the specimen deformed by route A. Based on these results, it was found that ECAPed Al-Ti alloy specimen by route A has highly anisotropic microstructure. However, both ECAPed specimens with routes A and Bc have no anisotropic wear property. That is because the wear property of the Al-Ti alloy specimen depends on the shape of the Al3Ti particle. From these results, it was found that SPD induced by ECAP is an effective processing method to make homogeneous wear property for the metallic material containing platelet solid-particles.