【摘要】 应用XRD、SEM、TEM以及短时拉伸试验研究了钙对镁合金组织和性能的影响。结果表明:铸态下,含钙镁合金主要由镁基体和晶界处的离异共晶组织(Mg+Mg2Ca)组成;固溶时效后,晶界处的离异共晶组织消失,代之以颗粒状的Mg2Ca相。铸态合金的常温力学性能较差,但固溶时效后其常温力学性能显著提高,并且在高温短时拉伸时仍然能保持较高的强度。随着含钙量的提高,晶界离异共晶量增加,铸态和时效态的室温抗拉强度和伸长率均下降,时效态高温短时抗拉强度增加,但伸长率仍有所下降。更多还原

【Abstract】 The microstructure and mechanical properties of magnesium alloys containing Ca in various contents were investigated using X-ray diffraction, SEM, TEM, and tensile tests. The as-cast Mg-Ca alloys were composed of Mg matrix and divorced eutectic (Mg+Mg2Ca) formed along the grain boundaries. After solution-aging treatment, the divorced eutectic disappeared, and discrete granular Mg2Ca particles were formed in the grain boundaries. The room temperature tensile properties of as-cast Mg-Ca alloy were poor, but they were appreciably enhanced after solution-aging treatment. The Mg-Ca alloys, after solution-aging treatment, showed considerable strength when subjected to a transient tensile tests at an elevated temperature of 200 ℃. With increasing the Ca contents, the quantity of the grain boundary divorced eutectic increased, the room-temperature tensile strength and elongation of both the as-cast and aged alloys decreased, the elevated-temperature transient tensile strength of the aged alloys increased, and elongation decreased.更多还原