High Speed Grinding Mechanism Of Nickel Superalloy With Single Abrasive Grain

Nickel superalloy has been widely used in aerospace, shipbuilding and chemical industry owing to its excellent mechanical performance. However, nickel superalloy is a typical of difficult-to-cut materials. In recent years, high speed grinding technology has been developed rapidly because it has many advantages. This provides a new way for grinding nickel superalloy. However, the high speed grinding mechanism has not been researched deeply, which leads to low grinding efficiency, poor stability of processing quality and short wheel life in the high speed grinding process. As a simplified model of the grinding, the grinding technique with single abrasive grain is an effective way to explore the mechanism of the complex grinding. Based on the disadvantages of single abrasive grain grinding experiments in the previous research, a new program of single grain grinding test is proposed and carried out in this paper. High speed and ultra high speed grinding mechanism of nickel superalloy with single grain is investigated. The main research work is described as follows:(1) Based on the theoretical analysis of the single grain trace in grinding, the path of the single grain which accorded with the actual grinding trace has been proposed. Accordingly, the test device was designed and developed for the high speed grinding with single grain.(2) Experiment of high speed grinding (80~150 m/s) of nickel superalloy GH4169 with single grain has been conducted. Both the chip morphology and groove morphology were detected, which were compared with the experiment results of the conventional grinding with low wheel speed. The grinding force of single grain was measured. The relationship between grinding force and grinding speed was analyzed in the condition when the maximum undeformed chip thickness was fixed.(3) The grinding deformation mechanism of nickel superalloy GH4169 has been discussed in the case of high speed grinding. Meanwhile, the chip formation of the superalloy GH4169 in grinding with single grain is simulated by finite element method. Then the effects of grinding speed on the chip morphology, the grinding force and the grinding temperature were investigated. Finally, the chip morphology of nickel superalloy GH4169 was predicted in the case of the grinding speed from 200 to 500 m/s. At the same time, the chip formation mechanism was discussed.