Author:

Keywords:

Cu-Au, ordering, deformation, X ray diffraction, 0204 Condensed Matter Physics, 0912 Materials Engineering, 0913 Mechanical Engineering, Materials

Abstract:

Copper-gold alloys containing 30 at.% gold were converted into powder, by filing at room temperature and at 77K, and into plates by rolling at room temperature (reduction in area 90%). The ordering was studied by means of X-ray diffraction techniques. The powder samples in the as-deformed or recrystallized condition were annealed at different temperatures and iced-brine quenched. In filings, prepared at room temperature, the satellites and the central superstructure reflection grew at about the same rate, implying the direct formation of Cu/sub 3/Au/sub II/ from the SRO-state and not via the Cu/sub 3/Au/sub I/-phase. The degree of order was lower in the cold-worked samples, whereas the Cu/sub 3/Au/sub II/-content appears to be little affected by cold-work. Of the plates, annealed for various times at 361 degrees C, the microhardness vs time curve displays two maxima, the texture parameter /b T//sub 220/, i.e. the ratio of peak intensities, varies in phase with the 1 macr 1 macr 1 macr microhardness curve and recrystallization occurs immediately beyond each maximum. In between the two maxima, the original texture of the cold-worked sample reappears and from the second maximum on a cube texture develops