Yield strength behavior for rolled magnesium alloy sheets with texture variation

Property improvements in fine–grained Mg–Zn–Zr alloy sheets produced by temperature–step–down multi–pass rolling

“…Both the values are greatly higher than those of the extruded and rolled Mg alloys with an intense basal texture [7,31,32] (157e348 MPa mm 1/2 summarized by Yuan et al [31]), and even than the values of~300 MPa mm 1/2 for Mg alloys subjected to twinningeinduced deformation [8,33]. This is mainly attributed to the dramatically strengthening of {0002} pole intensity during rolling since precipitation is minimal, then resulting in a comparatively lower of friction stresses of~64 MPa.…”

“…As shown, after the fifth pass at~275 C and the subsequent sixth pass at~250 C, more refined structures with grain sizes of 7.8 mm and 5.1 mm are observed, respectively, and exhibit lower dispersions with Rds of~2.9. Few twins are detected, indicating that twinning deformation is remarkably suppressed by the refinement with the aid of an intense {0002} basal texture (shown below) [8,22]. Finally, a homogeneous microstructure with fine grains of 3.5 mm and Rd of~2.5 is achieved after the seventh pass at~240 C.…”

“…Strictly speaking, the two values, especiallys 0 , are also related to the presence of precipitations and its matching interface with the matrix to some extent [11]. In fact, it can be seen that the observed slopes are approximately 20 MPa mm 1/2 higher than those of fully annealed conditions with similar basal texture along both the RD and the TD [8,31] (154e164 MPa mm 1/2 for k), and could be well interpreted in terms of the continuous precipitation during rolling. Meanwhile, it is apparent that all the strengths along the TD are slightly larger than that along the RD ascribed to the larger dispersion of {0002} basal intensity toward the RD.…”

“…Texture together with its homogeneity, especially the intensity of {0002} basal texture [8], is another very important factor that enables mechanical properties to change remarkably, and could be estimated via both XRD and EBSD. Clearly, the diffraction intensity of {0002} basal peak shown in Fig.…”

“…The I{10e10}/I{10e11} also showed a slight decrease. Perhaps this is attributed to the increasing contribution of pyramidal < cþa> slip, since only {10e12} twinning and pyramidal slip can provide the deformation along the ceaxis [8,22].…”