Laser cutting of aluminium-alumina metal matrix composite

Laser cutting of monolithic materials like metals and alloys is well-established and is used extensively in various industries including aerospace, medical and automotive. However, laser cutting of anisotropic materials like metal matrix composites (MMC)is challenging due to the differences in the chemical and physical properties of the matrix and fibre reinforcement. This manuscript contains details and results of an investigation into laser cutting of 2 mm thick aluminium metal matrix reinforced with aluminium oxide fibre (Al MMC). The laser cutting mechanism and the influence of laser cutting parameters on the quality of cuts were examined in detail. The experimental results demonstrated that the laser cutting mechanisms of fibre reinforced MMCs are vastly different from the mechanisms observed in laser cutting of monolithic metals and alloys. The Al₂O₃ fibres within the MMC are not vaporised but are removed along with the molten, low melting point matrix materials. A thin and uniform layer of Al₂O₃ was been deposited over the cut surface which can be advantageous for applications that involve moving gases or fluids, for example, aero-engine cooling holes.