AZ31マグネシウム合金板の温間プレス成形性に及ぼす成形温度の影響 Influence of forming temperature on warm press formability of AZ31 magnesium alloy sheets
Press forming test apparatus to be able to change from room temperature to 673 K was developed for evaluating characteristics of warm press formability in magnesium alloy sheets. By using of this apparatus, a cylindrical cupping test for deep drawability, a bore expanding test with flat punch for stretch-flanging formability, and a hat-shape bending test for shape fixability have been carried out on two kinds of AZ31 magnesium alloy sheets (A material and B material). As a result, limiting drawing ratio (LDR) becomes 2.5 at the time of forming temperature 433 K, and forming height in the cylindrical cupping test is higher for larger punch shoulder radius. In the stretch-flanging formability, bore expanding ratio can get maximum value at 473 K and is constant at more than 473 K. Shape fixability is improved as the forming temperature is raised, and at 573 K, spring back is reduced to almost zero. A characteristic of warm press forming varies with a production condition of materials, and has strong correlation with mechanical properties at forming temperature.
軽金属 57(1), 2-5, 2007-01-30
The Japan Institute of Light Metals