高能超声在制备颗粒增强金属基复合材料中的作用

采用高能超声处理方法制备了致密度高、增强颗粒均匀分散的ＳｉＣ／ＺＡ２２基复合材料．对复合材料制备过程中高能超声的作用机理、有效作用范围进行了分析．结果表明，在试验所用高能超声处理条件下（２０ｋＨｚ，１ｋＷ），熔液中能造成瞬时局部高温、高压的声空化效应与具有较高速度和加速度的声流效应的协同作用，是高能超声处理技术在制备颗粒增强金属基复合材料时改善增强颗粒与基体合金润湿性，并使颗粒在合金中弥散分布的原因．而高能超声在熔体中有限的有效作用区域，要求利用该技术制备复合材料时，必须在工艺上保证熔体的各个部位均能受到高能超声的有效作用才能获得优质的复合材料

Effects of High Intensity Ultrasonic during MMCp Fabrication

With high intensity ultrasonic treatment (20 kHz, 1 kW), sound SiC/ZA22 composites were prepared with homogeneously dispersing reinforced particles. The mechanism and effective range of the high intensity ultrasonic treatment were studied systematically. It is shown that the cooperation of acoustic cavitation which induces instantanenous high local temperature and pressure and high speed streaming can improve the wettability between molten matrix and reinforcement and make the particles dispersing homogeneously. In order to obtain prime composites, we must make sure that every part of the melt is treated by high intensity ultrasonic because the limited acoustic effective range.