形变热处理对Mg-6Zn-1Zr-1.5Y合金组织与性能的影响

Effect of Hot Extrusion and Aging Treatment on Microstructure and Mechanical Properties of Mg-6Zn-1Zr-1.5Y Alloy

摘要:

研究挤压比及时效处理对Mg-6Zn-1Zr-1.5Y合金组织及力学性能的影响规律，初步分析了该合金在形变热处理过程中的强化机制。结果表明：随着挤压比增加，其延伸率逐渐升高，而其强度则先升高后下降；时效处理后，挤压比λ=10的棒材的强度和延伸率都有所下降，λ=13的棒材强度和延伸率都有所升高，λ=25的棒材的强度提高而延伸率降低。该合金的主要强化机制包括: 细晶强化，加工硬化和时效强化；合金热挤压后的性能取决于细晶强化和加工硬化的交互作用，时效后的性能取决于时效强化与加工硬化的交互作用

Abstract:

The effect of hot extrusion and aging treatment on microstructure and mechanical property of Mg-6Zn-1Zr-1.5Y alloy was investigated and the strengthening mechanism was clarified. The elongation increased and the strength first increased and then decreased with increasing extrusion ratio. Mg3Y2Zn3 phase precipitated during hot extrusion and the dislocation density decreased during aging treatment. The strength and elongation of the extrusion bar (λ=10) decreased, the strength and elongation of the extrusion bar (λ=13) increased, and the strength increased and the elongation decreased of the extrusion bar (λ=25). The major strengthening mechanism is aging strengthening, strain-hardening and Hall-petch strengthening. The mechanical property depended on Hall-petch strengthening and strain-hardening after hot extrusion, and depended on aging strengthening and strain-hardening after aging treatment