MONOCRYSTALLINE WELDING OF MATERIALS HARDENED IN ONE DIRECTION Russian patent published in 2014 - IPC B23K26/34 

FIELD: process engineering.

SUBSTANCE: invention relates to laser buildup of hardened weld seam on structural element substrate from refractory alloy with directed orientated of dendrites. Powder is fed and laser beam is directed on substrate surface to smelt fed powder and substrate surface layer to obtain dendrites 31 in surface layer oriented in direction of substrate dendrites 32. Parameters of laser buildup are as follows: beam scanning rate, laser power, beam diameter, powder stream focus and/or powder flow rate are set to ensure local orientation of temperature gradient 28 at crystallisation front 19 smaller than 45° towards substrate dendrite direction 32 for dendrite 31 in substrate 4. Beam scanning rate is set equal to 30-100 mm/min, preferably 50 mm/min and/or laser power is set equal to 200-500 W, preferably 300 W, and/or beam diameter at substrate surface is set equal to 3-6 mm, and/or powder flow rate is set to 300 mg/min to 600 mg/min, preferably 400 mg/min.

EFFECT: single direction of dendrite growth, complete melting of powder in the melt.

7 cl, 4 dwg