MICROSTRUCTURE IN Al-Ti BASE ALLOYS AFFECTED BY A REPEATED WORKING PROCESS

摘要

Research program of applying repeated working process similar to ECAP (Equal Channel Angular Pressing) to Al-Ti base alloys (Al-10mol%Ti-3.6mol%Mn Al-10mol%Ti-3.2mol%Cr) is underway to obtain a fine dispersion of second phase particles with high volume fraction. As a first step, in this study, a repeated working process was applied to the Al-Ti-Mn alloy ingot at 600°C. Although the bolts clamping the dies were seriously deformed at the first pass and further working became impossible, significant refinement of the second phase particles was observed. It was found from X-ray diffraction analysis that two intermetallic phases, Al_6Mn (or Al(13)Cr_2) and Al_3Ti with DO_(22) structure, were present together with aluminum matrix in the ingots, and that they slightly increased in amount when annealed at 650°C for 24h.