No abstract

Nickel base and titanium base materials have been widely applied to engines in aerospace industry, and these engines are essential components of airplanes. The machining characteristics of aerospace materials may cause machining cutters to be worn down in a short time and thus reduce the accuracy of processing. The plasma-assisted machining adopted in the research is a kind of the complex machining method. In the cases of nickel base and titanium base alloys, the method can heat workpieces in an extremely short duration to soften the materials for the ease of cutting so that the cutting force, cutter wear, and machining cost will all be reduced. The research adopted plasma heating to soften parts of the materials and aimed to explore the heating of nickel base alloy. The temperature variation of the materials was investigated and measured by adjusting the current and feed velocity. Moreover, Inconel-718 superalloy was adopted for the comparison with nickel base alloy for the observation of the influence and change brought by heat, and the method of exponential smoothing was adopted to conduct the prediction and analysis of thermal diffusion for understanding the influence and change brought by electric current on nickel base materials. Finally, given the current from 20 A to 80 A and feed velocity from 1,000 mm/min to 3,000 mm/min, the influence of thermal diffusion was investigated and the related model was built.

Nickel-based alloys are widely applied in the industry. It is important to think highly of production quality and speed. Nickel-based alloys have high strength, high heat resistance, and corrosion resistance. During the cutting process, these characteristics will bring a lot of processing problems such as surface roughness, machining efficiency, and tool wear. Therefore, through the composite concept, computer numerical controlled lathe with plasma welding machines to improve processing problems was combined. Plasma-assisted machining involves plasma heat source heating to the surface of the partial material before the cutting process. Partial material will increase the temperature to achieve heatsoftening effect. This approach could reduce the hardness of material and help to conduct the cutting process with tools. The conventional machining was compared with plasma-assisted machining by experiment. Their different cutting speed, feed rate, cutting depth, and the current size were investigated. The result shows that plasma-assisted machining could reduce the cutting forces efficiently.