Research on High Volume Fraction SiC<sub>p</sub>/Al Removal Mechanism under Condition of Ultrasonic Vertical Vibration

Abstract

High volume fraction SiCp/Al is a new kind of composite materials, with broad application prospect in the aerospace, automobile manufacturing and other fields, and gradually become the key materials in the field of high technology. But with its internal high hardness material (SiC) content increases and the material removal mechanism is not very clear, general machining is more difficult and seriously hinders the development of the material. With the advantages of high material removal rate, effectively processing all kinds of complicated curved surface, especially, in the thin-walled parts processing, milling occupies an absolute advantage. In order to solve the processing problems of high volume fraction SiCp/Al composites, basing on the theory of ultrasonic and brittle material removal. PCD milling experiment of SiCp/Al was carried out with homemade ultrasonic milling system under the condition of ultrasonic vertical vibration, the material removal mechanism was studied, the 2d and 3d model of surface formation was established, finally, microscopic structure on the surface of the workpiece was analyzed by metallographic microscope and electron microscope. Research results show that: SiC particle removal form can be divided into type of cut, pulled, pressed and crack penetration; under the condition of ultrasonic, probability of SiC particles cut type increased, this forms better surface smoothness; due to tool and chip separation characteristics and the ultrasonic impact effect on material, the removal mechanism of SiCp/Al is close to the plastic material, forming better surface quality under condition of ultrasonic. This paper verifies that the ultrasonic vertical vibration cutting is an effective machining method for high volume fraction SiCp/Al.