Effect of chamfer width and chamfer angle on tool wear in slot milling

Effect of chamfer width and chamfer angle on tool wear in slot milling

Finding an optimum tool edge geometry to improve tool life reliability during machining is of great importance, especially when manufacturing parts with high accuracy and or high productivity demands. This work aims to increase knowledge to help steel component manufacturers to minimize tool cost and downtime while maintaining sustainable manufacturing. The models described in this paper include the relationship between chamfer width and chamfer angle. Single tooth milling is applied for the verification of the theories presented in the paper.

The abrasive and adhesive wear pattern after about 10 min of machining. Insert with negative chamfer, 0.20-mm wide and 20° angle.

Rake wear

Abrasive wear and adhesive wear are the two primary mechanisms involved in the deterioration of the rake. Figure above shows abrasive wear patterns on the rake, close to the edge, and degenerated edge line due to the adhesive wear. Greater chamfer width and angle result in higher cutting forces and thus higher temperatures. High cutting temperatures soften the tool material and, combined with high cutting forces on the ceramic inclusions in the workpiece material, such as aluminum oxide, which has a Micro Vickers hardness value of about 2000, cause the abrasive particles to cut deeper marks and accelerate the abrasive wear. On the other hand, the adhesive wear probably decreases slightly at the same time as the temperature increase since the material is not adhered to the tool as easily. Higher cutting forces generate more forced vibrations which fatigue the cutting edge and in the end cause chipping.

Flank wear

More wear is often found near the corners. This is because the chips grow in width and become larger than the machined slot. The cutting geometry is made to handle this problem but is never perfect. Consequently, the chips are pressed against the machined shoulders. Hence, the corners of the edge become more stressed, which leads to slightly more significant wear near the corners of the flank.

Wear models, including the relationship between chamfer width and chamfer angle, are presented. The results add understanding of how to decrease the wear speed, i.e., minimize abrasive and adhesive wear, which cause the measurable flank and rake wear, and at the same time prevent chipping. Read more about it at Springer.

Learn more and read the full article on Springer here: https://rdcu.be/dG4Ru

Authors of this article; Kourosh Tatar and Inge Svenningsson.