GHERA Cristian "Politehnica" University of Timisoara

Spoluautoři MITELEA Ion, BORDEASU Ilare, OANCA Octavian Victor

The paper presents a new procedure for bronze surface hardened by using intensive heating with laser beams (over 103 °C/s) which superficially melts the material. Afterwards the whole mass of the piece is subjected to blast cooling. For the used experimental conditions it was obtained a fine quenching microstructure with high harnesses, till 350 HV 0.5. The resulted structure has extremely fine grains which give an excellent resistance to cavitation erosions, because displacements are heavily suppressed. Secondary, the residual compression tensions existing in the superficial layer delay the initiation of the cracks. Tertiary, the effects of bubble implosions are attenuated as a result of the holes realized on the surface by the laser beams treatment. Finally, the power of the laser beams upon the increase of the cavitation resistance was put into evidence.