Manufacturing methods for hardening–restoration of quick-wearing parts by the use of laser heating

Nezavisimosti ave, 65, building 6, Minsk, Belarus, 220013 

Ph.: 375-172-310 045

Ph/fax: 375-172-939 223


Professor O. Devoino 



The know-how of surface laser hardening is based on displacement with definite speed of laser focused beam along designed trajectory. High rates of heating and cooling of thin surface layer (103... 109 к/c) are due to high densities of the power in the treatment spot (up to 109 W / м2); provide specific surface structure formation with an unique complex of physical –and mechanical properties. The heat treatment of a surface is provided without a solid heating-up of the parts, that makes possible such kind of hardening for intricately shaped parts, large-sized ones, to name but a few, hardening of which is impossible by the traditional methods.

The laser hardening is effective for carbon alloyed tool steels, cast irons and hard alloys.

The process can be conducted both with flashing, and without flashing of a surface with a conservation of the source microtexture. The structure of a finely dispersive needle-like martensite with 60-65 НRС hardness is formed, and the surface layer microhardness reaches (1-1,2) 104 MPa for steels with carbon content up to 0,95-1,0 %. Wear resistance is increased by 2 to 3 times as compared with volumetric-hardened steels. The layer ranges in depth from 0,3 to 1 mm.

The know-how of laser alloying provides an application of a layer of the alloying constituents on a hardened surface and its consequent penetration by a laser beam. In addition, with all advantages of laser hardening the method allows to perform the materials hardening (strengthening) which are not exposed to one, as an example, low-carbon steels, austenitic steels, non-ferrous alloys. The choice of alloying coating and laser treatment conditions provides a means of the layers formation with a required complex of physical-and mechanical properties. The layer ranges in depth from 0,3 to 1 mm. The enhancement of wear resistance lies in the range of 3 … 5 times as compared with volumetric-hardened articles.

The know-how of a laser facing with protecting coatings is used for the restoration of worn-out parts. For this purpose the oxyfuel gas spraying of a coating by powdered self-fluxing alloys is made previously on a part, and thereafter a laser flashing of the given layer. The complementary alloying of the coatings during flashing provides the coating properties correction as required by the working conditions of the parts.

The laser know-how is introduced in a number of industries, as an example, for the parts hardening for auto-tractor equipment (camshafts and crankshafts of internal combustion engines), oil and petrochemical machinery (shafts of pumps, impellers in places of their glove seals as well as a number of other parts).