利用光学显微镜、材料试验机及扫描电镜,研究了机械振动、超声及超声-机械振动复合作用,对熔模铸造AZ91D-3Ca阻燃镁合金凝固组织和力学性能的影响。结果表明:经复合处理后,合金的凝固组织改善效果最好,其初生相由发达的树枝晶转变为细小的等轴晶,第二相呈条状或颗粒状;合金的抗拉强度和伸长率最高,与未处理的试样相比分别提高了109.6%和52.2%。 The effects of mechanical vibration, ultrasonic and ultrasonic-mechanical vibration on the microstructure and mechanical properties of the cast AZ91D-3Ca flame-retardant magnesium alloy were studied by optical microscope, material testing machine and scanning electron microscope. The results show that the solidification microstructure of the alloy has the best improvement effect. The primary phase changes from developed dendrites to fine equiaxed grains, and the second phase is strip or granular. The tensile strength and elongation of the alloy The highest rate, respectively, compared with the untreated sample increased by 109.6% and 52.2%.