Laser heat treatment effect on fatigue of hinged cantilever beams

The paper considers the effect of laser hardening treatment of steels on the fatigue strength of materials. The statement of efficiency of laser processing for formation of hard surface layer of processed surface which protects from wear is substantiated in relation to a hinge design in agricultural machines placed on a cantilever fastened beam which is a hinge axis. The phenomenon of reduction of fatigue characteristics of structural steels after laser treatment is investigated. Influence of fatigue loading on beam durability is analyzed. On the basis of experimental data analysis, the conclusion is formulated that the surface defects in the form of wells which are formed under the influence of laser pulse play an important role during the pulse laser treatment. Particular attention is paid to the role of residual stresses generated by the thermal effects of the laser. On the basis of this research, it is recommended that laser hardening treatment should be carried out, the pulse energy of which does not lead to surface melting

Improving the mechanical properties of zirconia in instrument bearings

The article presents the issues of replacing leucosapphires in jeweled bearings of the axes of precision instruments with nanostructured crystals of partially stabilized zirconia. The statement is substantiated that doping with rare earth elements provides an improvement in the performance properties of precision instruments by improving the mechanical properties of bearing materials. The efficiency of doping of zirconia crystals with cerium and neodymium oxides is studied. It was found that doped crystals have increased plasticity, which provides an increase in the crack resistance of crystals. Special attention is paid to the issues of increasing the survivability of high-speed rotor bearings by replacing the thrust bearing of leucosapphire with nanostructured crystals of partially stabilized zirconia doped with cerium and neodymium. The efficiency of improving the mechanical properties is confirmed by the X-ray phase analysis of crystals. The phase composition is studied by Raman scattering and the lattice parameters are determined. The increased crack resistance of the thrust bearing is confirmed by tests performed using the kinetic microhardness method

Improving the mechanical properties of zirconia in instrument bearings

The article presents the issues of replacing leucosapphires in jeweled bearings of the axes of precision instruments with nanostructured crystals of partially stabilized zirconia. The statement is substantiated that doping with rare earth elements provides an improvement in the performance properties of precision instruments by improving the mechanical properties of bearing materials. The efficiency of doping of zirconia crystals with cerium and neodymium oxides is studied. It was found that doped crystals have increased plasticity, which provides an increase in the crack resistance of crystals. Special attention is paid to the issues of increasing the survivability of high-speed rotor bearings by replacing the thrust bearing of leucosapphire with nanostructured crystals of partially stabilized zirconia doped with cerium and neodymium. The efficiency of improving the mechanical properties is confirmed by the X-ray phase analysis of crystals. The phase composition is studied by Raman scattering and the lattice parameters are determined. The increased crack resistance of the thrust bearing is confirmed by tests performed using the kinetic microhardness method