Understanding local cutting features affecting surface integrity of gear flank in gear skiving

Abstract

In gear skiving, large variations in cutting features significantly affect the cutting condition and surface integrity of a newly formed gear flank (NGF). This study aimed to improve the understanding of the effects of local cutting features on the surface integrity of approach and recess NGFs from the resulting microstructure produced by the multiple radial-infeed (MRI) strategy. For the first time, the boundary of the NGF regime and associated local cutting features were calculated from the uncut chip geometry (UCG) using a novel boundary-based level contour method. The theoretical and experimental results revealed that the local rake angle and uncut chip thickness are the most influential factors altering the plastic deformation conditions of the approach and recess NGFs. For the finishing pass, the uncut chip thickness developments within approach and recess NGFs were elucidated, showing the burnishing regime dominated the recess NGF formation. The strain–stress characteristics of the recess NGF show the strain-hardening effect due to the severe plastic deformation. Kernel average misorientation mapping showed a partial reduction in the misorientation angle under the recess NGF. This points to the accumulated deformation in the interaction between successive skiving passes further facilitating the localized recrystallization. Proposed local cutting feature calculations can be applied for further kinematic parameter optimization and MRI infeed rate design.