Revisiting the Calibration of Friction in Metal Cutting

Abstract

This article reexamines pin-on-disc and ring compression tests in order to understand which technical modifications and operating parameters have to be revised and controlled in order to obtain valid estimates of the coefficient of friction for metal cutting applications. The methodology draws from the development of new equipment and testing procedures focused on the interaction between surrounding medium, surface roughness, and freshly formed surfaces to the independent determination of the coefficient of friction.

Assessing the coefficient of friction obtained from experimentation with pin-on-disc and ring compression tests against that acquired in orthogonal metal cutting conditions allows concluding that simulative tribology tests, performed in dry friction conditions, with adequate control of surface morphology and under a protective shield of argon, are capable of modeling contact with friction in good agreement with real metal cutting.

The identification of operative testing conditions that are capable of merging the coefficient of friction supplied by different tribology tests ensures a unified view of tribologists and metal cutting experts on the accuracy, reliability, and validity of simulative tribology tests for metal cutting applications.

KEY WORDS:

• Metal Cutting
• Pin-on-Disk Test
• Ring Compression Test
• Coefficient of Friction
• Surface Roughness
• Surrounding Medium

Acknowledgments

Review led by Gary Barber