Influencing the Properties of the Generated Surface by Adjusted Rake and Clearance Angles in Side Milling of Aluminum Matrix Composites with MCD-Tipped Tools

Abstract

The application of aluminum matrix composites (AMCs) allows the reduction of moving loads for increased efficiency in modern technical systems. However, the presence of reinforcing particles leads to challenges in machining of AMCs, typically requiring diamond cutting materials. Single-edged MCD-tipped tools are used to investigate the influence of different clearance and rake angles on the resulting surface properties in milling, while the cutting parameters are kept constant. The specimens are manufactured from an aluminum wrought alloy comparable to EN AW-2017, reinforced with 10 vol.% of SiC particles. The surface properties are evaluated considering the surface structure, the residual stress state, and the microstructure of the surface layer. A clearance angle of the minor cutting edge of about 3° on average leads to the lowest Rz values and a reduced fluctuation of surface roughness values. Using a tool with a positive rake angle of 5° entails the highest absolute values of the compressive residual stresses and an increase compared to the initial state of up to about 290%. The results contribute to an understanding of the relations between tool geometry and the generated surface properties required for a targeted enhancement of the functional performance when machining AMCs.

Keywords

• aluminum matrix composite
• clearance angle
• MCD
• milling
• rake angle
• residual stress state
• surface integrity
• surface layer
• surface properties
• surface structure