WEAR RESISTANT COATINGS ON BASED BORIDE PHASES FORMED IN THE MAGNETIC FIELD ON ALLOYS
- 1 Department of metal science and heat treatment, National Technical University of Ukraine "Igor Sikorsky Kiev Polytechnic Institute", Kiev, Ukraine
- 2 V. Bakul Institute for Superhard Materialsof the National Academy of Sciences of Ukraine
In this paper we study the structure, phase composition, microhardness, wear resistance boride coatings obtained on metals and alloys at complex saturation with boron and copper in various physical and chemical conditions, namely carrying satiation without application of an external magnetic field (EMF) and in its simultaneous imposition . Studies have shown that the use of EMF when applying boride coatings allows in 1.5 – 2 times reduce the duration of saturation detail and get coatings with high hardness and wear resistance.
Established that the application EMF on carbon steels formed a continuous, homogeneous boride layer, thickness is 2 times higher than the boriding without EMF. On the diffraction patterns of the surface layers of boride coatings obtained after boriding at application EMF fixed presence phases FeB and Fe2B, the redistribution of the proportion of boride phases, the change of the crystal lattices and the decrease in the volume of the unit lattice phase FeB. When the complex is saturated steel 45 with boron and copper diffusion layer is composed of the phases FeB, Fe2B and Cu. Chemical heat treatment with the simultaneous action of EMF leads to the formation of phases in the diffusion zone FeB and Cu, crack resistance layers obtained after saturation with boron and copper increases to 2.23 MPa · m0,5 compared to 1.12 MPa · m0,5 for boride coatings obtained without action EMF .
Formation diffuse boride layers under the action EMF improves tribological characteristics and leads to an increase in wear resistance of 2.2 – 2.6 times.