A STUDY OF RAPIDLY SOLIDIFIED AL3TI INTERMETALLICS WITH ALLOYING ADDITIONS

Al//3Ti, Al//3Ti plus 0. 6%B, Al//3Ti plus 3. 5%Mn, and Al//5CuTi//2 were studied to investigate the effect of rapid solidification on microstructures, phases, and hardness. Rapid solidification of Al//3Ti refined the microstructure and increased the hardness but did not change the structure of the equilibrium phases. The additions of B or Mn introduced second phase particles which dispersion strengthened the matrix. Al//5CuTi//2 had the Ll//2 structure with a point of 1350 degree C and exhibited lower hardness than the Al//3Ti-based material with the DO//2//2 structure. RS did not change the Ll//2 structure and increased the hardness only slightly. Qualitatively, all of the compounds appeared brittle.