Optimization of energy consumption in coating removal for recycling scrap coated cemented carbide tools using hybrid laser-waterjet

Abstract

In order to purified recovery of scrap cemented carbide, stripping of coatings was mandatory as engineering tools for improving service life were almost modified with anti-wear coatings. However, the low efficiency of current coating removal technologies leaded to the overmuch energy consumption, it was of great importance to achieve energy conservation to relieve the environment impact because of sustainable development. Reducing the energy consumption during processing could significantly improve the environmental performance of manufacturing systems. According to the energy consumption characteristics of hybrid laser-waterjet machine, a multi-objective optimization model for energy prediction with key parameters under actual constraints is constructed to trade off two responses: the cutting specific energy consumption (CSEC) and the processing time, which is transformed into a single-objective model and then solved by genetic algorithm. Simultaneously, the orthogonal experiment is proposed to identify the parametric influence on the multi-objective optimization and to validate the feasibility of the proposed model with the comparisons between single-objective and multi-objective optimization. Finally, the comparisons about energy consumption, carbon emission and the mechanical properties between high temperature oxidation method and hybrid laser-waterjet technology are carried out. The results indicate that larger feed speed and larger laser offset distance can benefit the energy conservation due to the shortened processing time. The multi-objective optimization model realizes about 80% of energy conservation compared to minimum CSEC, and 40% of which compared to minimum processing time. Contrasted to the energy conservation and substrate quality after processing, the hybrid laser-waterjet technology is much better than the high-temperature oxidation method.