| The effects of aging treatment has been investigated in rapidly quenched Al-3.5Swt% Cr-lwt%X(X=Zr, V, Ti, Ni, Mn, Si) alloys. Specimens are aged from room temperature to 600℃ for 1hr. Vickers microhardness, electrical resistivity, microstructure is examined closely to study the aging phenomena in the alloys. Thermal stability is an important factor in designing alloys. In this respect, Al-Cr alloys containing V, Zr or Ti is better than the others. Al-Cr-Zr and Al-Cr-V is also desirable for age hardening, so Vickers microhardness is 120-126 at 450℃. The TEM results show that Al-Cr-Si alloy isn`t suitable for high temperature property because of high diffusivity and segregation. But the alloy including V or Zr is composed of homogeneous fine precipitates which are spherical-type. |
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