| Summary: | 碩士 === 國立勤益科技大學 === 機械工程系 === 102 === Nickel-base superalloys are mainly used in the field of aerospace engine components.Taking a Boeing 787 as an example, this plane has about 2.4 million aircraft
components of about which 40% are nickel-based alloys. There has been a move in recent years to improve the fuel efficiency of engine due to high oil prices, which are being developed with high-pressure and high-temperature engine designs where the amount of nickel-base superalloys, which are more heat-resistant, have gradually increased to more than 50%. At room temperature nickel-base superalloy shave a high tensile strength, and when the temperature is increased they have a high melting point and high intensity r’ and r’’ precipitation. Friction between the tool and fragments within the machine can lead to residual heat being generated, which may result in producing dislocations in r’ and r’’ precipitation, so increasing the strength of the
nickel superalloy machine could cause tool wear and damage.
Plasma assisted machining is the use of a plasma heat source on a partial surface of the material before the cutting machining action. This is undertaken with a local
temperature increase to reach a thermal softening effect to the extent of thermo-physical melting, so that decomposition and evaporate occur when cutting the softened material. With regards to tool wear, online detection can be performed to detect when the blade needs to be replaced, which reduces the amount of measurement error and so establishes a tool lifetime relationship.
This study looks at a comparison of general machining plasma assisted processing, and uses different experiments to investigate the heat-affected thickness, cutting depth, as
well as the amount of current used. From the experimental results, plasma assisted machining shows a substantial improvement in comparison for cutting force, tool wear, tool lifetime and general machining.
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