Surface hardening and tempering by means of an oscillating laser beam

Industry is increasingly demanding technological solutions for diversifying and customizing its products. Laser technology, given its attributes, is an ideal tool for the personalized treatment of surfaces, above all, due to the flexibility it offers, thanks to the possibility of shaping or distributing the beam energy in a localized and efficient way.

This work presents a study of the surface hardening and tempering processes using an oscillating laser beam, shaped by means of a high-dynamic galvanometric mirror scanner and generated by a continuous wave diode laser.

The study focuses on the one hand, on determining the influence of the oscillation frequency parameter during the surface hardening process of 42CrMo4 steel.

On the other hand, the effect of the surface tempering process, carried out on a region of the material previously hardened by the same laser source, on the temperature, microstructure, stress state and hardness of the treated steel, is investigated.

Finally, a particular shaping strategy is proposed to obtain an optimized design of equivalent laser energy distribution, capable of simultaneously hardening and tempering the surface of the material, without the need to perform both processes separately.