| Abstract Scope |
Asymmetric rolling, i.e., upper and lower rolls having different circumferential speeds, is a novel technique to improve ductility of Mg alloys. A newly developed TZ73 Mg alloy was squeeze cast, homogenized at 300oC for 24 h, rolled at 350oC by symmetric and asymmetric rolling, and annealed at 215oC for 30 minutes. The microstructure was characterized by X-ray diffraction, scanning electron microscope equipped with energy dispersive X-ray spectroscopy and electron backscattered diffraction. A weakening of basal texture with a concomittent increase in ductility was observed for asymmetrically rolled sheet, while retaining the same strength as in symmetrically rolled sheet. Thus, tensile properties of 0.2% PS = 290 MPa, UTS = 332 MPa and El = 13% in hot-rolled, and 0.2% PS = 182 MPa, UTS = 282 MPa and El = 21% in annealed conditions were obtained for asymmetrically rolled sheet, which are extremely good for a rolled Mg alloy sheet. |