Hybrid laser-mechanical machining of ceramic matrix composites

Abstract

Advanced materials like ceramic matrix composites (CMCs) exhibit superior thermomechanical properties crucial for addressing 21st century engineering challenges, however machining of these material is difficult using conventional manufacturing methods. This study investigates hybrid (sequential) laser-mechanical machining (HLMM) of 6 mm thick alumina oxide (Al₂O₃) based ceramic matrix composite, consisting of Nextel™ 610 alumina fibres (>99% Al₂O₃) in an alumina matrix (>99% Al₂O₃), commonly known as Ox-Ox CMC. Through systematic comparison of standalone laser cutting, mechanical machining, and HLMM, this study demonstrates that HLMM effectively addresses the limitations of conventional processes. Results show HLMM achieves a 70% reduction in cutting force (from 645 N to 189 N) and 167% increase in tool life compared to standalone mechanical machining, while improving surface quality by 74% (from Sa 38.25 µm to 8.0 µm) compared to laser cutting. HLMM exhibits an overall cutting speed of 560 mm/min for 6 mm thick Ox-Ox CMC, significantly outperforming conventional mechanical machining (2–13 mm/min) while maintaining superior surface quality.