2008 年 49 巻 6 号 p. 1262-1269
Hot rolling was conducted for Mg–6 mass%Al–2 mass%Ca alloy containing insoluble second phase particles and the mechanical properties of the rolled sheets were examined. The alloy used for rolling contained spherical particles with the size of 1.5 μm mainly in the grain boundaries. The amount of edge crack in the rolled sheets decreased at the rolling temperatures above ∼623 K. The highest strength and moderate elongation were obtained when the alloy was rolled at 623 K. The processing conditions for good workability under a given microstructure of the workpiece were considered from a viewpoint of relaxation of stress concentrations at the particle-matrix interface during rolling, and hot working diagrams were constructed. In order to attain good workability under the existence of relatively large second phase particles of 1.5 μm, it is required not only to activate the non-basal slip but also to make use of diffusional relaxation.
