A predictive thermomechanical model for peck drilling

Drilling processes produce significant heat due to friction and material deformation, which can lead to tool wear, surface damage, and residual stress in the workpiece. To mitigate these effects, the peck drilling strategy was developed, incorporating periodic tool retractions to lower peak cutting temperatures and enhance chip evacuation. Consequently, accurate temperature distribution predictions are essential to improve drilling performance and ensure part quality. Few works in the literature focused on peck drilling operations, whose success is mainly influenced by the mitigation of the cutting temperature. To fill this gap, this study introduces a comprehensive predictive framework for evaluating cutting forces and temperatures in peck drilling. It combines an analytical force model with two distinct thermal analysis methods: an analytical technique and a Finite Volume Method (FVM) simulation. A novel oblique cutting model, grounded in Oxley's machining theory and incorporating the Johnson–Cook material model, is proposed. The analytical thermal approach extends the infinitesimal point-source method to represent transient heat conduction in finite media, while the FVM simulation numerically models heat transfer and material removal dynamics. To validate the framework, an experimental campaign was conducted under various cutting conditions. Results demonstrate the model's capability to reliably estimate cutting forces and temperature distributions across a wide range of parameters. The average prediction errors were 4.66% for cutting power, 7.45% for cutting forces, and for maximum temperature, 8% with the FVM and 11.64% using the analytical method. The developed framework lays the groundwork for future investigations into the impact of lubrication strategies on peck drilling.