STANDARD AND SCANNING LASER HARDENING PROCEDURE

Laser hardening is one of the most common laser applications. The standard "wide-spot" method uses a direct diode laser with a large spot which moves evenly along a treated area. The scanning method uses a small laser spot in combination with a laser scanning head, which allows very fast laser spot displacements. This technique is based on very fast laser beam sweeping which is perpendicular to main laser treatment trajectory. The fast sweeping beam acts like a continuous wide laser spot. These two laser hardening techniques are described and compared in this contribution. Experimental procedures and results examples are introduced. HPDD (High Power Direct Diode) laser with spot dimensions 6 x 12 mm was used for wide-spot hardening and a solid state disc laser with spot diameter 800 mu m and laser scanning head allowing spot displacement speed up to 21.5 m/s were used for scanning method hardening. Results comparison and main advantages or drawbacks of both the methods are discussed in this contribution.