LASER MARKING METHOD Russian patent published in 2001 - IPC

FIELD: processes for marking articles with multilayer coatings in different branches of machine engineering. SUBSTANCE: method comprises steps of selecting power P and radius r of focusing spot of laser irradiation in order to provide power density corresponding to its value set for heat strengthening of coating material and in order to provide width h of marking line corresponding to its set value. Radius r of focusing spot satisfies to next relation r = (h³/8-3•Pτtgϕ/πL_и)^1/3, τ where ϕ is duration of laser irradiation pulse, L_i is an angle half of light cone opening of laser irradiation. Le is specific energy of evaporated coating. Laser irradiation is focused on surface of article for treating pattern in such a way that number of pulses directed onto each element of pattern is determined according to given formula n = (l³+3•l²•r/tgϕ+3•l•r²/tg²ϕ)•π•tg²ϕ•L_i/3Pτ, where l-thickness of coating. Such relations allow to provide heat strengthened base material of article, to seal microflaws (that were filled by coating material) on surface of base material and to receive marking pattern on surface of article or to remove material of outer coating in treated portions and to heat strengthen coating material under it. EFFECT: enhanced quality of marking. 2 cl, 2 dwg