This article deals with a mutual comparison of indexable cutting inserts of the CNMG 120408 type from two different manufacturers during the machining of hardened steel AISI 4337 and austenitic stainless steel AISI 316 L. The main goal is to analyse the different wear processes depending on the difference in the manufacturer’s design and also depending on the properties of the different machined materials. The progress of the wear of the main spine of the tool, the types of wear and the service life of the cutting edge were monitored, with the achievement of the critical value VB_max = 300 µm being the standard. In addition to the wear of the inserts, the production of chips was monitored in terms of their shape, average size and number of chips per 100 g of chips produced. In order to understand the relationships arising from the obtained data, an SEM equipped with an elemental analyser was used to analyse the coating layers and the substrate of the unworn inserts and the types of wear and the intensity of the surface damage of the worn inserts. A several-fold difference in the lifetime of the cutting edge was found, both in terms of design and in terms of the selected machined material, while in both cases the cutting edge with Al₂O₃ and TiCN layers of half thickness achieved a better result in liveness. From the point of view of chip formation, very similar results in shape and average length were observed despite the different designs of chip breakers. Cutting inserts with half the thickness of the coating layers achieved longer cutting edge life in the non-primary material application compared to the target workpiece material. At the same time, it was observed that a thinner coating layer has a positive effect on chip formation in terms of its length and shape.

The article deals with the analysis of the mechanical properties of the newly designed aluminum alloy Al-Si7CrMnCu2.5. The research was carried out in order to map a new alloy with a certain addition of chromium and manganese from the point of view of mechanical properties and their changes after heat treatment (hardening, artificial aging) with defined parameters. Specifically, properties such as strength limit, yield strength, ductility, hardness, and microhardness were analyzed, both in the cast state and after heat treatment. The alloy was designed as an alternative to the standard Al-Si alloys already used in practice (AlSi7Mg, AlSi7Mg0.3, AlSi8Cu2Mn, AlSi8Cu3), which are mainly used in the production of engine parts and other components for the automotive and aviation industries. As can be seen from the presented results, the experimental AlSi7CrMnCu2.5 alloy exceeds the properties of the other selected alloys by tens of percent already in the cast state in many parameters. After heat treatment, the results achieved are comparable to the mentioned alloys, and in most cases, their values exceed them, especially in terms of ductility and hardness.