Formation of Hybrid Metal Matrix Composites by Melt Stirring with Ultrasonic Vibration Based on Interfacial Control

研究了超声辅助放热反应和改善润湿性对Al_2O_3颗粒在铝合金熔体搅拌中的作用。将Al_2O_3颗粒与预混的镍粉一起添加到熔融的Al-5mass%Mg合金中，并在1023 K和氮气气氛下以16.7 rps的转速搅拌。然后用陶瓷板将超声波传输到熔融铝合金中。将超声振动应用于铝合金熔体搅拌中，不仅改善了镍粉在铝合金熔体中的表观润湿性，而且使镍粉在铝合金熔体中充分溶解。通过施加超声振动促进镍铝化物形成的放热反应。该放热反应导致熔融铝合金的局部温度升高，这也改善了润湿性。超声辅助下的镍铝化物生成放热反应有助于增加被包裹的Al_2O_3颗粒，并有助于制备无孔隙的复合浆料。

This study is aimed at examining the influence of ultrasound-assisted expthermic reaction and improved wettability on the incorporation of Al_2O_3 particles into molten aluminum alloy in melt stirring. The Al_2O_3 particles with premixed nickel powder were added on molten Al-5 mass %Mg alloy and stirred at a rotation speed of 16.7 rps at 1023 K in a nitrogen atmosphere. The ultrasound was then transmitted to molten aluminum alloy with a ceramic plate. The application of ultrasonic vibration to melt stirring not only improve the apparent wettability, but also the nickel powder to dissolve thoroughly into molten aluminum alloy. The exothermic reaction of nickel aluminide formation is promoted by applying ultrasonic vibration. This exothermic reaction leads to a local temperature rise of molten aluminum alloy, which also improve the wettability. The ultrasound-assisted exothermic reaction of nickel aluminide formation contributes to an increase in engulfed Al_2O_3 particles and also the preparation of pore-free composite slurry.