Reducing engine oil and fuel consumptions by multidimensional laser surface texturing on cylinder surface

Abstract

• Proposed the multidimensional laser surface texturing (MLST) process, based on the engine motion characteristic. • Established hardware and software systems and optimized the parameters of MLST process. • The ablating position of each laser pulse is manipulated, and various depths of micro dimples are fabricated by controlling the repeat times of overlapped laser pulses. • Developed the post-process for MLST process, based on the finishing honing process to remove the recast bulges (RCB) induced by laser ablation. • Tested four schemes of cylinder liners (one prototype, three MLST) on a single cylinder diesel engine at rated power and speed. • One of MLST scheme reduced engine oil and fuel consumptions simultaneously. The optimization of cylinder surface topography draws immense amounts of researches, since it has far-reaching effects on engines’ overall performances. In order to promote the lubricity of ring/bore interface, the present study developed the multidimensional laser surface texturing (MLST) process, which fabricates controllable arrays of micro dimples on cylinder surface. The MLST process was achieved by a series of innovations, including its hardware and software systems, and optimization of process parameters and efficiency. A post-process was developed based on the finishing honing process to remove the recast bulges (RCB) induced by laser ablation. Additionally, the cylinder liners with different surface texturing schemes were bench tested on a single cylinder diesel engine. The experimental results indicated that near TDC (top dead center) region and piston skirt contacting region (SKIRT) were two high-impact regions for the technical efficiency of the MLST process. Benefiting from the reasonable optimization of oil distribution and enhanced hydrodynamic lubrication, the MLST process was able to reduce engine oil and fuel consumptions simultaneously. This paper provides a comprehensive introduction of equipment, pre- and post-process, and capacities of the newly developed surface modification technology.