The influence of speed on material removal mechanism in high speed grinding with single grit

• The new method for single-grit grinding is applied to study the speed effect.
• The critical thickness of chip formation was quantitatively analyzed.
• The speed has a significant impact on high speed grinding process.
• Speed effect provides new thoughts to understanding the high speed grinding mechanism.

In this paper, the effect of speed on material removal was investigated by single grit grinding of the GH4169 super alloy which is difficult to machine, with a new test method. During the tests the whole material removal process, was observed and then the critical thickness of chip formation was quantitatively analyzed. In order to provide insight into the speed effect, the grinding forces, chip formation and pile-up ratio were investigated. It was found that the stages of material removal process changed with the grinding speed, and the graphical relationships between grinding speed and the critical thickness of chip formation, grinding forces and the pile-up ratio were found to have a common characteristic, namely a common turnover point which was about 100 m/s. This trend in the results is attributed to alternating predominance between the strain hardening and thermal softening effects. The results of this study demonstrated that the grinding speed has a significant impact on material removal mechanism, and also provide a basis for sound understanding of the high speed grinding process of difficult to cut materials.