Influence of SiC particle volume fraction and texture on the surface properties in milling of AMCs with MCD-tipped tools

摘要

Modern technical systems aim for increased performance and efficiency, which can be realised by applying lightweight materials to reduce moving loads. Regarding this, particle-reinforced aluminium matrix composites (AMCs) state a promising approach, enhancing the mechanical strength compared to unreinforced alloys. However, the presence of ceramic particles leads to challenges in machining as well. The majority of research on machining focuses on the influence of the cutting parameters. Additionally, other vital aspects are the material composition and the texture, especially with reference to powder-metallurgically produced and extruded AMCs. Side milling of different SiC particle-reinforced AMCs with a matrix comparable to the alloy EN AW-2017 and particle fractions of 5, 10, and 15 percent by volume is addressed using a single-edged MCD-tipped tool. Moreover, different orientations of the generated surface referring to the extrusion direction are considered. The evaluation is focused on the surface properties, including areal roughness parameters, surface imperfections and the residual stresses of the generated surfaces compared to the initial stress state. Increased particle volume fractions lead to reduced five-point heights, decreased valley void volumes, and increased absolute values of the second compressive residual stresses, when machining perpendicular to the direction of extrusion. For any of the investigated composites, machining results in significantly increased absolute values of the compressive residual stresses. The investigations enhance the fundamental understanding of the material influence when milling AMCs using MCD-tipped tools. Comprising different composites with the same matrix alloy and type of reinforcement, the examinations provide a comprehensive database on the material influence.