Research on strengthening mechanism of AZ63 cast magnesium alloy based on precipitation phase orientation control

A high strength and toughness AZ63 cast magnesium alloy whose ultimate tensile strength, yield strength and elongation at room temperature respectively reached 319 MPa, 160 MPa and 7.6%, was developed by combining the alternating-temperature ultrasonic melt treatment and T6 heat treatment. The high as-aged tensile properties of the alloy with the alternating-temperature ultrasonic melt treatment are mainly attributed to the remarkable increase of the β-prismatic precipitates with orientation relationships (ORs) of (3¯3¯0)β // (11¯00)α, [1¯11]β // [112¯0]α, thereinto the mentioned-increase is possibly related to that the solute-vacancy clusters along {01¯11} plane might serve as the nucleation points of the β-prismatic precipitates.