Experimental Analysis of Cutting Parameters of Ultrasonic Assisted Processing Honeycomb Composites

• Main Authors: WANG,WEI-SONG, 王維崧
• Other Authors: HUNG,JUI-PIN
• Format: Others
• Language: zh-TW
• Published: 2019
• Online Access: http://ndltd.ncl.edu.tw/handle/fsvsd2

碩士 === 國立勤益科技大學 === 機械工程系 === 107 === Nomex honeycomb composite materials have the characteristics of light weight, good thermal insulation performance and high axial strength of the expanded pores, so they are often used on aerospace structural components, such as the outer spoiler of the aircraft main engine and the turbine engine hood. However, due to the weak material strength in vertical direction of bonding ribbon, it is easy to produce burrs, deformation of material structure and rupture of Nomex bonded interface when processed by traditional processing methods. This seriously affects the processing accuracy and processing quality. Ultrasonic vibration assisted machining is conducted by using a cutting tool excited longitudinally with ultrasonic vibration. Compared with the traditional machining method, ultrasonic vibration assisted machining has the advantages of reducing machining resistance, improving machining efficiency, not easily generating blade edge and improving surface roughness. Currently, ultrasonic machining method has been applied to the processing of composite materials, but the optimal processing parameters required for Nomex honeycomb material have not been well established. Therefore, this study was aimed to investigate the machining behavior of the Nomex honeycomb composite materials with the use of ultrasonic processing method. The effects of the cutting parameters of ultrasonic vibration assisted with triangle cutter were mainly concerned. The main works include the establishment of the rotary working fixture for ultrasonic cutting experiment, and measurement of the cutting forces under different processing parameters by using dynamometer, examining the worn out of the cutting tool and machining quality of the specimens and finally the evaluation of the optimum processing parameters for improvement of the processing efficiency and tool life. According to the experimental results, the ultrasonic exciting power, feed rate and cutting angle show significant influences on the cutting forces. It is found that under specific ultrasonic power, increase the feed rate will produce higher cutting force, but easily to produce poor quality, however, at this moment, appropriately adjusting the exciting power to higher level will increase vibration amplitude and reduces the cutting force, which is favorable to proceed the machining with good surface quality. Regarding the wearing test, it is found that the tool life is greatly determined by the cutting force. A higher power used in machining greatly reduces the tool life. Summering the results, it can be concluded that appropriate exciting power and the feed rate can reduce the cutting force and increase the tool life with better machining quality. Finally, the experimental approaches proposed in this study can be applied to evaluate the variations of the cutting force with changing of the cutting parameters, which can further be used to assess the optimum combinations of the cutting parameters with higher processing efficiency and tool life when dealing with machining of different composite materials.