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在挤压温度400℃、挤压速度5 mm/s、挤压比25的条件下成形了外接圆准179 mm的ZK60镁合金工字型材。运用XRD衍射、光学显微镜、扫描电镜及室温拉伸等检测手段对它的组织和力学性能进行了研究。结果表明,挤压态ZK60镁合金主要存在α-Mg、MgZn2相和少量Mg2Zn11、Zn2Zr3相。合金晶粒受挤压作用而破碎,发生不完全动态再结晶,晶粒得到明显细化,并沿挤压方向呈流线分布。细小的第二相颗粒弥散分布于α-Mg基体。室温拉伸实验说明挤压态ZK60镁合金存在明显的各向异性,挤压方向试样抗拉强度最高(325 MPa),与挤压方向成45°的试样伸长率最高(23%)。
ZK60 magnesium alloy profile with circumscribed circle 179 mm was formed under the conditions of extrusion temperature of 400 ℃, extrusion speed of 5 mm / s and extrusion ratio of 25. Its microstructure and mechanical properties were studied by XRD, optical microscopy, scanning electron microscopy and room temperature tensile testing. The results show that there are mainly α-Mg and MgZn2 phases and a small amount of Mg2Zn11 and Zn2Zr3 phases in the as-extruded ZK60 magnesium alloy. Alloy grains crushed by the extrusion, incomplete dynamic recrystallization occurs, the grain was significantly refined, and was streamlined along the extrusion direction. Fine second phase particles dispersed in the α-Mg matrix. Tensile tests at room temperature show that there is obvious anisotropy in the as-extruded ZK60 magnesium alloy, with the highest tensile strength (325 MPa) in the extrusion direction and the highest (23%) in the 45 ° extrusion direction. .