A novel alternating-frequency ultrasonic melt treatment (AUMT) technology is used to refine the grain and improve the strength of AS41 magnesium alloy. The AUMT exhibits better grain refinement efficiency than the traditional 20 kHz single-frequency ultrasonic melt treatment method, showing the grain refinement efficiency up to 82.7%. The improvement of cavitation is suspected to be the reason for better grain refinement. The faster alternating time is beneficial to improve grain refinement efficiency. The AUMT also refines the Mg₁₇Al₁₂ and eliminates the agglomeration of Mg₂Si. Such microstructure evolution helps improve the tensile strength and elongation of AS41.

一种新颖的交变超声熔体处理（AUMT）技术用于细化晶粒并提高AS41镁合金的强度。AUMT的晶粒细化效率高于传统的20 kHz单频超声熔融处理方法，晶粒细化效率高达82.7％。空化的改善被认为是更好的晶粒细化的原因。更快的交替时间有利于提高晶粒细化效率。AUMT还提炼了Mg ₁₇ Al ₁₂并消除了Mg ₂ Si的团聚。这种微观结构的演变有助于提高AS41的拉伸强度和伸长率。