International Scientific Journals
of Scientific Technical Union of Mechanical Engineering "Industry 4.0"

Abstract: It was dedicated to solution of scientific and technical problem to increase the level of physical and mechanical and operational properties of the surface of steels by forming strengthened layers diffusion boriding and complex saturation boron and copper in a magnetic field.

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 · m^0,5 compared to 1.12 MPa · m^0,5 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.

In this paper was investigated the formation of complex diffusion boride layers on metastable austenite Cr-Mn-N steel powder method. Calculate the value of the diffusion coefficient in different physical – chemical conditions and the thermodynamic potential chemical reactions. Defined phase composition layers obtained on the metastable austenite Cr-Mn-N steel. It is established that the application of an external magnetic field (EMF) leads to a redistribution of the proportion boride phases in the surface layers, changes the period of crystal lattice and increasing the diffusion coefficient.

In this paper we study the structure, phase composition, microhardness, crack resistance, wear resistance boride coatings obtained at complex saturation with boron and copper in the application of an external magnetic field (EMF). Investigations have shown that this method allows the application of boride coatings in 1.5 – 2 times decrease the duration saturation detail, and receive coating with high hardness, wear resistance, crack resistance.

It is established that the application EMF formed a continuous, homogeneous boride layer with thickness coatings in 2 times higher than boride coatings without EMF for the equal duration of the process. When imposing EMF in boride layers observed the redistribution quantitative relation boride phases, namely: decrease of volume phase FeB, and on diffractograms surface layers boride coatings obtained after boriding fixed presence phases FeB and Fe₂B. After complex saturation boron and copper in the application of external magnetic fields fixed phases FeB and Cu.

The researches have shown that the highest spalling stress value is reached in boride phases, obtained in powder environments with copper powder at the application of EMF, and respectively is 420 compared with 225 MPa for coating obtained without EMF. Increased shear stress values in complex layers obtained after saturation with boron and copper caused by the formation of phases more viscosity, for which crack K_1c in 1.4 – 2.0 times higher than the initial boride phases FeB and Fe₂B.

Application of EMF at boriding improves tribological characteristics of coatings: decreases coefficient of friction and increase in 1.5 – 2.5 times wear resistance.

The results of research coatings coatings obtained after complex saturation boron and silicon in the powder environment on steel 45. Determine the thickness and microhardness of the resulting coatings, their phase and chemical composition. It has been established that the coatings obtained after complex saturation boron and silicon more plastic and have a 1.8 times higher fracture toughness (K_1c) and 1.5 times higher than the wear resistance as compared with coatings obtained by borating.

Investigated the wear resistance of coatings obtained by saturation with boron and copper under dry friction – sliding on the air, and found that the coatings obtained by saturation with boron and copper have 2 times better wear resistance than the coating after boriding. Found that the saturation of boron and copper complex provides optimal performance when wear boride phases, namely sufficient microhardness – 15.5 MPa, 0,5 0,5 low porosity, increase in viscosity layer, the value K reaches 2.1 MPa · m to compared with 1.2 MPa · m 1C without complex saturation and increasing stress chipping values to 290 MPa compared to 170 MPa for the boride layers.

It was investigated the structure, phase and chemical composition, thickness diffusion boride layers obtained after boriding and complex saturation boron and copper with simultaneous action an external magnetic field (EMF) on solid alloy T5K10. It was established that the application of an external magnetic field allows to intensify the process of diffusion saturation hard alloys boron and by 2 hours chemical – thermal treatment with simultaneous action EMF get such thickness diffusion boride layer which is formed by 4 hours chemical – thermal treatment without EMF. It was found increase microhardness diffusion layers formed on the hard alloys on 2 – 2.5 GPa (30 – 30.5 GPa) that is associated with a decrease areas of coherent scattering and as a result increase operating parts that work in conditions of intensive wear.

The results of studies wear resistance of boron coatings alloyed with Сu, V, Nb, Cr or Ti under dry friction – slip in the air, and it was determined that the best coatings are the boride layers alloyed with copper. Alloying with copper inereases wear resistance of boride layers in 3 times. When alloying of boride layers with niobium wear resistance increases in 2,8 times, with titanium – in 2,4 times, with chromium and vanadium – in 1,5 times. Wear resistance of boride coatings alloyed with copper under dry friction – slip 14 times higher than wear resistance of bronze of Cu – Al – Mn system and wear resistance increases when applying boride layers alloyed with copper.

In this paper it was investigated the formation of complex boriding diffusion layers on metastable austenite Cr-Mn-N steel powder method. Defined phase and chemical composition, thickness, microhardness and wear resistance obtained by layers of metastable austenite Cr-Mn-N steel. It is established that the application of an external magnetic field (EMF) leads to a redistribution of the proportion boride phases in the surface layers of the crystal lattice period changes. EMF allows in 1.5 – 2 times to reduce the period of saturation details, microhardness diffusion boride coatings increase to 20,5 – 21 GPa and increase their wear resistance in 2.4 – 3 times compared to steel without protective coating. Boriding a magnetic field will increase the microhardness boride coatings 6 – 7 GPa compared to the boriding without application of a magnetic field.

The results of studies on the application of complex boron coating powder method on hard alloys. Defined phase and chemical composition, thickness and microhardness of the coating on alloys.

It was established that after diffusion saturation of hard alloy in boron mixture for 4 hours formed coating with boride phases TiB, WB, CoB and WC, TiC, whose thickness is 50-60 microns. At complex saturation with boron and copper for 4 hours diffusion saturation formed coating with boride phases TiB, WB, CoB and WC, TiC and separate inclusions of copper with a thickness of the diffusion layer up to 70-80 microns.

Boriding and complex saturation with boron and copper allows in 2 – 2.5 times increase the microhardness of the surface layers of hard alloys, that in turn leads to increased wear resistance.

The results of studies wear resistance of boron coatings alloyed with Сu, V, Nb, Cr or Ti under dry friction – slip in the air, and it was determined that the best coatings are the boride layers alloyed with copper. Alloying with copper inereases wear resistance of boride layers in 3 times. When alloying of boride layers with niobium wear resistance increases in 2,8 times, with titanium – in 2,4 times, with chromium and vanadium – in 1,5 times. Wear resistance of boride coatings alloyed with copper under dry friction – slip 14 times higher than wear resistance of bronze of Cu – Al – Mn system and wear resistance increases when applying boride layers alloyed with copper.