Influence of Co contents and super-gravity field on refinement of in-situ ultra-fined fibers in Al-2.5Ni eutectic alloys

Abstract

We reported the influence of Co contents (0%, 0.1 at.%, 0.15 at.% and 0.2 at.%) and super-gravity field on the refinement of the in-situ eutectic structure in Al–Ni alloys. Our results indicate that trace amounts of Co addition (0.1 at.%) could lead to the refinement of ultra-fined Al3Ni fibers under both normal gravity and super-gravity field. The refining efficiency of the Co addition is significantly enhanced under super-gravity filed. In addition to the refinement of Al3Ni fibers, the coarse Al9Co2 phase (plate-like) can be observed under normal gravity field with Co content up to 0.2 at.%. Noted that the orientation relationship of the Al3Ni fiber with respect to Al matrix is adopted Al3Ni[010]//Al[1−12] based on the SAED pattern. The refinement mechanism of Al3Ni under normal gravity and super-gravity field was discussed in details.