METHOD OF PRODUCING MULTILAYER COMPOSITE COATINGS Russian patent published in 2016 - IPC C23C4/06 C23C4/129 C23C24/08 

FIELD: metallurgy.

SUBSTANCE: invention relates to metal science, chemical-thermal treatment of metal articles, to production of structural purpose nano-structured wear-resistant materials and can be used for machines parts durability increasing in industry. Method of multilayer composite coating from powder materials HVOF on metal article includes application of coating bottom layer with thickness of 20-100 mqm from mechanically activated powder Ni, central layer with thickness of 50-500 mqm from mechanically activated powder with shape memory effect based on TiNi and upper layer with thickness of 50-500 mqm from mechanically activated mixture of powders of B₄C, WC, (Cr₃C₂ or CSi), Co, Ni, C, with their ratio wt%: B₄C 35-80, WC 7-40, (Cr₃C₂ or CSi) 7-30, Co 1-5, Ni 4-7, C 1-3. It is followed by annealing at temperature of 600-800 °C for 0.5-1 hours. After application of central layer from alloy with shape memory effect based on TiNi performing its surface plastic deformation during heating at temperature range of Martensitic transformation by value to 4-10 % of layer thickness. Mechanical activation of powders and HVOF are performed in shielding atmosphere.

EFFECT: enabling higher strength characteristics and wear resistance of composite coatings using materials with shape memory effect.

4 cl, 1 tbl, 1 ex