Grain-boundary character distribution in recrystallized L12 ordered intermetallic alloys

The grain-boundary character distribution (GBCD) of cold-rolled and, subsequently, recrystallized Co3Ti and Ni3(Si,Ti) ordered alloys with an L12 structure was studied by the electron backscattered diffraction (EBSD) method, in association with texture. For comparison, the GBCD of recrystallized pure copper and aluminum was also determined. The recrystallization textures of the Co3Ti alloys as well as the Ni3(Si,Ti) alloy were significantly weak and different from those of the pure copper and aluminum with a strong cube texture. The GBCD of the Co3Ti alloys was characterized by a high frequency of Σ3 boundaries. On the other hand, the GBCD of the Ni3(Si,Ti) alloy was characterized by a lower frequency of Σ3 and higher frequency of random (e.g., Σ>29) boundaries than that of the Co3Ti alloys. However, the GBCDs of the Co3Ti and Ni3(Si,Ti) alloys were similar to each other and also quite similar to those of the pure copper and aluminum, when Σ3 boundaries are excluded from the GBCD. Based on these results, the formation mechanism responsible for the recrystallization textures and the grain-boundary structure and energy of the Co3Ti and Ni3(Si,Ti) alloys were discussed, in comparison with those of pure copper and aluminum.