Structure changes in laser modified surface layers of aluminium alloys
: Al-Zn, Al Fe, Al-Fe-Ni and steels: X45CrSi93, C50, as well as high s
peed steel S 6-5-2 are studied after laser remelting and laser alloyin
g by means of carbide (VC) and borides (CrB, VB2). The significant str
ucture refinement and formation of characteristic precipitates for rap
idly quenched microstructures are stated in aluminium based alloys. Fi
ne microstructure with martensite is observed in constructional steels
. Laser alloying of S 6-5-2 results in microstructure variation and ap
pearance of new types of precipitates enriched with W, Cr, and V. The
microstructure features are discussed in relation to the stated increa
se of hardness in all the cases of laser modification.