Ultrasonic Assisted Grinding Of Silicon Carbide Aluminum Matrix Composites

The SiCp/Al composite with 50% SiC particles has not only excellent properties of high specific modulus, low thermal expansion coefficient but also the key indicators of thermal conductivity, density and thermal deformation coefficient which are superior to general materials. This kind of composite has been widely used in the field of aerospace and military. Due to the high hardness of SiCp/Al composite, it is very difficult to process this composite, which has become one of the main factors restricting its wide application. Conventional machining methods can not meet the requirements of the composite’s processing, it has practical significance to study the composite’ precision processing technology and processing equipment.In this paper, by using a rotary ultrasonic vibration technology combined with ordinary grinding technology, the rotary ultrasound device, wheel jam mechanism, wheel wear mechanisms and the relationship with the grinding force are researched. By optimizing stepped solid horn’ design and parameters, as well as the way of the wheel connection, a acoustic vibration system is established, and the distance wheel protruding from the spring chuck end face was determined, which reducing the heat of the spring chuck and the loss of ultrasonic vibration energy. According to the characteristics of materials, resin bonded sub-block grinding wheel is selected, the grinding test platform is build on the three-axis CNC vertical machining center(Model: VMC850E). Based on a mathematical model of horizontal spindle surface grinding force which was proposed by previous scholars, the force form of single grain is analyzed and force formula model is deduced under the ultrasonic assisted condition.Through the analysis of test results and phenomenon: The wheel wear form under the condition of ultrasonic assisted grinding and ordinary grinding is basically the same. But at the same grinding parameters, the amount of wheel wear under the condition of ultrasonic assisted grinding is far less than that under ordinary grinding condition. Orthogonal test show that the feed rate of the grinding wheel affects the grinding wheel’s clogged volume most, and getting 180# wear particle wheel’ optimal grinding parameters under condition of ultrasonic assisted grinding. With the increase of the wheel wear and wear area, the grinding force is increasing, the amount of wheel’ surface wear and wear area are increasing when grinding depth is 0.015 mm.Meanwhile the actual grinding force’ upward trend has slowed. The results show that: To make ultrasonic assisted grinding become an efficient method of processing SiCp/Al composite, optimizing grinding parameters, grit size and grinding approach is an indispensable condition.