Wear of form taps in threading of Al-Si alloy parts: Mechanisms and measurements

Wear of form taps in machining of Al-12Si die-cast alloys has been a critical problem for automotive engine manufacturing. Poor quality of formed threads results in high rework cost, and scrap. This research is focused on investigating the wear mechanisms and quantify wear by developing new measurement metrics. In addition, a performance criterion has been proposed to limit machining and evaluate wear on form taps. Abrasion and Adhesion wear mechanisms have caused severe deterioration of lobes on the chamfered length of tap tools during form tapping. A detailed evaluation of the complexity of wear propagation has been presented for critical regions of a lobe in a form tap.