UBC Theses and Dissertations
Effect of alloying and cold rolling on the texture and mechanical properties of magnesium and magnesium-lithium alloys Wootton, George Claude
The effect of Li additions to Mg on the texture and mechanical properties in both the hot and cold rolled condition has been examined. It was found that using the texture goniometer (Schulz technique) only the surface texture is obtained. As a result average textures were prepared for each alloy. Lithium additions to Mg causes a loss in sharpness of the (0001) texture. No indication of a directional texture was found. The change in texture was explained successfully on the basis of deformation systems active during rolling. Cold rolling of the alloys caused a loss in sharpness of the (0001) texture for low Li alloys. In the high Li alloys (6 at. % and 12.4 at. %) a pronounced split occurred. A definite directional texture was observed on the surface of the cold-rolled low Li alloys but this disappeared in the "average" pole figure. Again the change in texture was explained on the basis of deformation systems active during rolling. Tensile tests of hot-rolled Mg-Li alloys agreed completely with those of Yoshinaga & Horiuchi (9) but showed some variance with those of Hauser, Landon, and Dorn (8). Tensile tests of cold-rolled Mg-Li alloys showed appreciable strain hardening and a loss of ductility due to the cold work. The higher the Li content the higher the rate of strain hardening observed for large increments of strain. The ratio of the transverse to longitudinal tensile properties decreased with increasing Li content. A qualitative explanation of the above was made on the basis of active deformation systems. Limited success was obtained in attempts to correlate mechanical properties and texture in low Li alloys. No attempt was made for high Li alloys.
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