1999 Volume 63 Issue 2 Pages 174-178
After heat-treatment at 1450 K for 24 h, L12-(AlMn)3Ti titanium trialuminides with and without quaternary elements of Zr, Ga, Ag or V were examined by X-ray powder diffraction profile analysis and optical and scanning electron microscopy after hardness tests.
The minimum load for crack generation during the hardness measurements decreased with the addition of Ag or Zr, however the minimum load increased with addition of V. The residual strain which was induced during milling of the alloy into powder exhibited a positive correlation with the minimum load, i.e., while the alloys with V showed a large residual strain, the alloys with other quaternary elements exhibited a smaller residual strain than that of the ternary L12-type (AlMn)3Ti alloy. The composition dependence of the ternary L12-(AlMn)3Ti single phase alloys was examined by the above mentioned the method. It was shown that the residual strain has the maximum value near the center of Al and Mn-rich corner of the single phase region in isothermal ternary phase diagram at 1425 K.
