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采用金属型铸造制备Mg-1Mn-1Zn(wt%)三元合金,并将其挤压成棒材。利用光学显微镜、扫描电子显微镜、浸泡试验法等研究了Mg-1Mn-1Zn合金的微观组织及其在0.9%NaCl溶液中的腐蚀行为。结果表明,Mg-1Mn-1Zn合金室温组织由树枝状的α-Mg相、非平衡共晶MgZn化合物相和脱溶析出的α-Mn相构成。热挤压使等轴晶粒沿挤压方向被拉长,呈现纤维状组织。Mg-1Mn-1Zn合金的平均腐蚀速率随时间增加逐渐降低。经过264 h浸泡后,挤压态Mg-1Mn-1Zn合金的平均腐蚀速率为0.44 mm/a,比铸态合金的低26.7%。
A Mg-1Mn-1Zn (wt%) ternary alloy was prepared by metal casting and extruded into bars. The microstructure of Mg-1Mn-1Zn alloy and its corrosion behavior in 0.9% NaCl solution were studied by optical microscopy, scanning electron microscopy and immersion test. The results show that the room-temperature microstructure of Mg-1Mn-1Zn alloy is composed of dendritic α-Mg phase, unbalanced eutectic MgZn phase and α-Mn phase eluted and eluted. Hot extrusion of equiaxed grains along the extrusion direction is elongated, showing fibrous tissue. The average corrosion rate of Mg-1Mn-1Zn alloy gradually decreased with time. After 264 h soaking, the average corrosion rate of Mg-1Mn-1Zn alloy was 0.44 mm / a, which was 26.7% lower than that of as-cast alloy.