Extensive research has been conducted to investigate the wear behaviour of cutting tools machining steels, cast irons, Ti- and Ni-alloys. However, it exist a noticeable research gap when it comes to wear of polycrystalline diamond (PCD) tools during machining of aluminium. Given the expected increase in demand for aluminium components to replace steel in the automotive sector as a result of the transition from internal combustion engine vehicles to electric cars, driven by their superior strength-to-weight ratio, it is imperative to improve the efciency and capabilities of PCD cutting inserts while machining aluminium. Sandvik Coromant conducted an intensive machining test campaign to gain a comprehensive understanding of how this wear manifests. As a result of their research, a hypothesis was formulated suggesting that attrition wear occurs. The hypothesis proposed that, during the machining process, diamond grains become loosened from the PCD edge, thus damaging the cutting insert.

The objective of this master’s thesis is to validate the hypothesis put forward by Sandvik Coromant. To understand attrition wear, a laboratory tribological test was designed using a pin-on-disc confguration to specifcally induce attrition wear to the PCD inserts. Sandvik Coromant supplied both worn and unworn PCD inserts for this study. The worn inserts were analysed with respect to their dominant wear mechanisms after being subjected to severe machining tests in the company, while the unworn inserts were used for the pin-on-disc test campaign.

After analysing the tribological test results and characterising the inserts using various techniques, such as light optical microscopy (LOM), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and three-dimensional proflometry, it was observed both test methods exhibited the same two types of wear phenomena. The frst phenomenon, known as micro-wear, was identifed by the presence of scratches on the rake surface, resulting from the detachment of diamond micro-fragments from cracks within the diamond grains. The second phenomenon, called macro-wear, was characterised by the presence of grooves caused by the detachment of diamond grains from the insert edges. Same wear behaviour patterns were observed in both test methods, indicating that the identical wear mechanisms were present. Thus, validating the hypothesis put forward by Sandvik Coromant.