碳化硅颗粒增强铝基复合材料(SiCp/Al)具有优异的物理及力学性能,但是其二次加工极为困难。仿真和试验研究了 SiCp/Al 复材的磨料电化学射流加工。结果表明,随着铝基体的去除,SiC 增强体与铝基材之间的结合界面不断减小,界面的疲劳寿命随界面面积减小而呈现若干数量级式降低。当结合界面面积下降到较低水平时, SiC增强相会从基体材料上脱落,同时在加工表面留下微坑。加工表面的粗糙度与这些微坑的数量和尺寸高度相关。 SiC 增强相尺度越大或含量越高,则加工表面越粗糙。
Abstract
Silicon carbide reinforced aluminum matrix composites (SiCp/Al) exhibit excellent properties and performance in fields of aerospace
electronic packaging
precision instrumentation and automotive industry. The SiCp/Al composites are hard-to-machining materials due to different physical properties between reinforcement material and matrix material. This study investigated removal mechanism of the reinforcement in abrasive assisted electrochemical jet machining (AECJM) of SiCp/Al composites through simulation and experiments. The results show that the lifetime of the bonding interface between SiC and matrix decreases in several orders of magnitudes with decrease of bonding area. The SiC reinforcement can be extracted out when bonding area drops off to a low level. This results in many micro pits left on the machining surface. The roughness of machining surface is highly relevant to numbers and size of these micro pits. Larger size or higher volume fraction of the reinforcement will result in rougher machining surface.