Process characteristics of laser-assisted micro machining of SiCp/2024Al composites

Micro machining has attracted great attention, and micro components made of hard-to-machine material are broadly applied in aerospace and automobile areas. Laser-assisted machining is an effective machine method for hard-to-machine materials. Combining the laser heating with conventional machining will be benefit for the machinability. In this study, an experimental investigation of laser-assisted micro machining of SiCp/2024Al composites was conducted. The aim of this study is to investigate the machining characteristics of SiCp/2024Al during laser-assisted micro machining (LAMM) in terms of cutting force, surface integrity, chip formation, and tool wear. L16 (type B) Taguchi orthogonal array was designed and the results are analyzed by ANOVA method. It is found that thrust force is the dominant force during experiment compared with main cutting force. There is 27% decrease in thrust force when laser power increased from 0 to 31 W which shows marked effect on cutting force. Adhesion wear and abrasive wear on flank face play a major role during LAMM when continuous chips were produced. The variation of flank wear VBmax is calculated by mean value, and the result shows that tool wear decreased 38% when laser power increased to 31 W. The experiment results show that the LAMM is benefit for the surface quality by small cutting depth and high laser power. There is 38% decrease in Ra when 31-W laser power was used compared with conventional machining. In terms of LAMM mechanism, there are two parts involved in. In one side, the material will soften because of high temperature by laser. In the other side, there are numerous aluminum oxide nanoparticles produced in the cutting area during LAMM. The mechanism of nanoparticles functioning, ball bearing effect, mending effect, and tribo-film effect are included in LAMM which affected the tribological behavior.