Creep regimes for directionally solidified Al-Al3Ni eutectic composite

Creep characteristics of Al-Al₃Ni eutectic composites directionally solidified at 2.2 × 10^-2 mm/s were determined over a wide range of stress and temperature. Four distinct regions of creep were observed. The rate controlling mechanisms for the four regions appear to be high-temperature dislocation climb in the Al matrix, low-temperature climb in the Al matrix, boundary sliding, and a mechanism involving deformation of the Al₃Ni fibers. Creep rates of the Al-Al₃Ni composite are several orders of magnitude smaller than for pure Al, and apparently, in the regions where deformation of the Al matrix is rate controlling, only a very small fraction of the matrix is deforming during creep of the composite. Formerly Graduate Student, Department of Mechanical and Industrial Engineering, University of Manitoba