The formation and development of cracks in samples made of ferromagnetic material, cast iron grade SCh 35, which are in a uniformly magnetized state under the influence of an internal magnetic field with a strength of more than 20 kA/m, has been studied. The anisotropic nature of quasi-brittle fracture and the magnitude of mechanical stresses at which fracture occurs are shown. Cracks propagating along magnetic field lines dominate. A possible reason for this is the magnetic interaction between the surfaces of the microcrack.

The results of microstructural studies, the microhardness distribution, and the estimation of abrasive wear resistance of structural 30KhGSA steel samples hardened during continuous irradiation with a multichannel (48 beams) CO 2 laser are presented. Fine martensite forms in the hardened zone and the steel has a high hardness and abrasion resistance.

Metallographic studies and tests for abrasive wear resistance are performed for a Ni – Cr – B – Si coating obtained by laser powder cladding with the help of a multichannel (40 beams) CO 2 laser. Efficiency of repeated laser recrystallization of the surface layers of the coating is demonstrated. This treatment can be used to form structures with different values of dendritic parameter and affects positively the wear resistance of the coating. The wear characteristics are shown to depend linearly on the dendritic parameter, which may be used as a criterion of wear resistance of coatings.

Reaction-bonded silicon carbide materials have been produced by infiltrating molten silicon into porous bodies consisting of silicon carbide, carbon black, and tungsten-core silicon carbide fibers. Their microstructure and mechanical properties have been studied as functions of reinforcing fiber content. Their bending strength, hardness, and modulus of elasticity have been shown to drop with increasing fiber content because of the increase in the porosity of the composite. At the same time, the fracture toughness of the composite rises to 5.2 MPa m(1/2) as the fiber content is raised to 8%. Thus, the mechanical properties of the composite can be improved by optimizing its microstructure and reinforcing fiber content.

The structure formation in corrosion-resistant steel during laser melting is studied. The results of investigation of the morphology and the granulometric and chemical compositions of a CL20ES steel powder, which was prepared by melt dispersion with a high-pressure inert gas, are reported. It is shown that samples characterized by the highest density and microhardness are prepared using a converging laser beam.

The abrasive wear resistance of tool steel samples hardened with a multichannel CO 2 laser are tested. Laser hardening is shown to increase the abrasive wear resistance by a factor of 2.5–6. No cracks, pores, and blowholes in the laser-hardened zones are observed.

Results are given for a study of alloy Ti – 6Al – 4V microstructure and microhardness prepared by object electron-beam synthesis (OEBS).

The possibilities of exerting a contactless effect on the process of laser treatment by external electrical and magnetic field are investigated. The schemes of coupling the field sources with laser equipment are described and the experimental data on the effect of the external fields on laser welding of carbon and stainless steels are presented.

The process strength of high-speed steel subjected to laser treatment is studied. It is shown that gas laser cutting of working surfaces of separating dies of coordinate turret presses faced with high-speed steel yields crack-free cut surfaces with good enough quality and reduces the volume and the time of finishing mechanical treatment of the working surfaces.

Results of a study of the effect of diamond smoothening on the microhardness of deposited high-speed steel in the laser-affected zone and on the quality of surface after gas laser cutting are presented.