(東北大學 材料電磁過程研究教育部重點實驗室，沈陽110004)
摘 要: 采用連續(xù)功率超聲對AS41鎂合金熔體進行孕育處理，研究超聲處理功率(強度)、處理時間和處理溫度等工藝條件對其凝固組織的影響規(guī)律。通過對凝固金相和低倍組織觀察以及XRD和Mg2Si相的點陣常數(shù)計算，結(jié)果表明：連續(xù)功率超聲孕育處理可以顯著細化AS41鎂合金的凝固組織，晶粒尺寸僅為無超聲處理時的30%~50%；適當提高超聲強度和處理溫度以及適當延長處理時間均可增強細化效果。優(yōu)化的處理條件如下：超聲強度為30~40 W/cm2，處理時間為50~80 s，處理溫度為650~700 ℃。此外，超聲處理也使Mg2Si相細化和球化，Mg2Si相的點陣常數(shù)也發(fā)生明顯變化。
關(guān)鍵字: AS41鎂合金；熔體；超聲孕育處理；凝固組織
（Key Laboratory of Electromagnetic Processing of Materials, Ministry of Education,
Northeastern University, Shenyang 110004, China）
Abstract:Continuous power ultrasound was applied to inoculating the AS41 melt, and the effects of inoculating conditions including ultrasonic power (intensity), treating time and treating temperature on the solidification microstructures were investigated. According to the metallographical and macroscopical observation together with the XRD pattern and the calculation of Mg2Si phase lattice constant, the results indicate that the continuous power ultrasonic inoculation treatment can refine the grain size of AS41 magnesium alloy markedly, and the grain size with ultrasonic treatment is only 30%−50% as that without ultrasonic treatment. The grain refinement is improved by enhancing ultrasonic intensity, elevating treating temperature (melt temperature), or prolonging treating time. Its optimum condition is that the ultrasonic field with intensity of 30−40 W/cm2 treats AS41 melt in the temperature range of 650−700 ℃ for 50−80 s. In addition, the ultrasonic treatment also leads to the refinement and spheroidization of Mg2Si and the change of its lattice constant as well.
Key words: AS41 magnesium alloy; melt; ultrasonic inoculation; solidification microstructure
