1995 Volume 36 Issue 11 Pages 1363-1371
Based on the continuum mechanics of textured polycrystals (CMTP), the effect of the scatter width of texture on the yield loci and R values of pure aluminium and A5083 alloy polycrystalline sheets with different texture components has been analyzed and examined in this study. First, by means of the best fits between the yield loci of the CMTP and the yield strengths measured from uniaxial tension, plane strain tension and biaxial stretching tests as well as the analysis of texture distribution, a quantitative relation between the exponent n in the CMTP yield function and the scatter width of texture ω has been determined empirically. Then, using the empirical equation and the CMTP yield function, R-values were calculated for pure aluminium and A5083 alloy sheets with various texture components. The following results have been obtained: (1) The changes of scatter width of texture have a significant influence on R values in the rolling plane, especially for the peaks of in-plane R values; (2) the yield locus calculated from the empirical equation and CMTP function is in good agreement with that predicted by the Taylor and Bishop/Hill model for cube texture (ω=5°); (3) R values predicted from the empirical equation and the CMTP by assuming ω=0° correspond to the previously reported data calculated from the other analytical approach for aluminium single crystal sheets of several ideal orientations being typical of the texture components in aluminium sheets; (4) R values calculated from the empirical equation and CMTP function are very well consistent with the experimental data measured in uniaxial tension tests for pure aluminium and A5083 alloy polycrystalline sheets with different texture components.