Surface reconstruction of porous substrates in sintered bronze by cw-high power diode laser

The present investigation deals with the application of a continuous wave-high power diode laser to modify the surface of porous substrates made from spherical particles in sintered bronze. In particular, the influence of laser power and interaction time on the capability of the laser processing to restructure the substrate morphology was investigated. Scanning Electron Microscope (SEM) and contact-gage surface profiler were used to analyze the evolution of the substrate morphology after laser treatments, whilst their mechanical properties were evaluated by micro-hardness and scratch tests.The experimental findings showed a decrease in the surface roughness of the porous substrates after laser treatments of ∼70%. In addition, an improvement in micro-hardness, scratch and wear resistance could also be achieved. Indeed, large laser power combined with high scan speed took to the most attractive results, thus favoring the onset of a promising morphological structure and the establishment of improved hardness and scratch resistance.

► Laser reconstruction is an emerging technology in the field of mould manufactured by rapid prototyping.
► Laser reconstruction process is based on the melting and subsequent re-solidification mechanism.
► Considerable improvement of roughness parameters is achievable by diode laser surface treatment.
► Densification process is induced by laser polishing treatment on sintered bronze.
► A sealing effect of the surface porosity in sintered material improves mechanical proprieties.