| Summary: | 碩士 === 國立中興大學 === 機械工程學系所 === 107 === In recent years, with the demand of various fields, the advancement of industrial technology has gradually shifted to the development of Advanced Composites Material,such as special materials that can withstand high temperatures, high toughness and high chemical stability, etc.,And in the aerospace industry,the most representative material is Inconel 718. Due to its special material behavior, such materials tend to deteriorate in machining quality during processing.Due to its material behavior this material is often referred to as difficult-to-cut materials. Drilling is one of the most common processing methods in the industry,it’s often being the first process in the all methods, It has proved that ultrasonic assisted drilling have the effct of to promote the hole quality,but the most of the study are focus on how much hole quality can be improved by using ultrasonic assisted drilling and how much processing energy is needed. That is the reason of the study will establishing a correlation through the experimental plan of Taguchi method about the relationship between the cutting force and spindle motor power and machining quality of drilling and tool wear.
According to the results, the effect of using ultrasonic assisted drilling on the hole surface quality after drilling was reduced by about 73% ,and was reduced by about 118% in cylindricity. The experiment with the Taguchi method can find that the parameter that has the greatest influence on the quality after processing is the feed per tooth.The cutting force and spindle motor power can be found that as the amount of workpiece removal increases and the cutting force also increases. The surface roughness can be found that will rise rapidly in the initial stage of cutting, and then tend to be steady until the tool VB wear value exceeds 0.3 mm, and the surface roughness will gradually deteriorate. From the cylindricity, it can also be seen that as the amount of workpiece removal increases, the cylindricity also tends to deteriorate. Based on the measured on-line data and the machining quality, the Pearson correlation coefficient is calculated for the amount of workpiece removal. It can be found that the correlation coefficient is as high as 80% or more. Both have a fairly high positive correlation. The Pearson correlation coefficient of cutting force and tool wear and workpiece removal is as high as 99%. The main contribution of this research is to establish the reference index of the feasibility of online evaluation of drilling quality and its relationship with tool wear through online measurement and post-processing product quality measurement and tool wear measurement data. This relationship evaluates the surface roughness, cylindricity and tool wear value of Inconel 718 drilling by the measured cutting force and spindle motor power.
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