Complicated wear-resistant parts made by selective laser melting (SLM) of powder material based on compositions of metal and ceramics can be widely used in mining, oil engineering, and other precision engineering industries. Ceramic–metal compositions were made using nanoscale powders by powder metallurgy methods. Optimal regimes were found for the SLM method. Chemical and phase composition, fracture toughness, and wear resistance of the obtained materials were determined. The wear rate of samples from 94 wt% tungsten carbide (WC) and 6 wt% cobalt (Co) was 1.3 times lower than that of a sample from BK6 obtained by the conventional methods. The hardness of obtained samples 2500 HV was 1.6 times higher than that of a sample from BK6 obtained by the traditional method (1550 HV).

The paper considers the problem of increasing the wear resistance of steel products. For the first time, the technology of anodic plasma electrolytic sulfiding is proposed to increase the wear resistance of low-carbon steel. The composition, structure, and frictional properties of modified surface layers after sulfiding have been studied. The type and mechanism of wear are determined. The influence of the sliding speed of the sample over the counter body on the friction and wear resistance of the samples after processing is analyzed. The possibility of saturation of low-carbon steel with sulfur in an electrolyte with sulfur compounds is shown. The iron sulfide FeS in the surface layer is found. It has been established that the thickness of the sulfide zone and the relative amount of FeS in it have a positive effect on reducing the coefficient of friction and mass wear. The greatest decrease in the friction coefficient by 5.5 times and weight wear by 64 times occurs after sulfiding at 500 °C for 10 min. It was found that the mechanism of wear of sulfided samples is fatigue wear during dry friction and plastic contact.

Spray drying is a widely used method of converting liquid material (aqueous or organic solutions, emulsions and suspensions) into a dry powder. Good flowability, narrow size distribution, and controllable morphology are inherent in powders produced by spray drying. This review considers the granulation factors that influence the final properties of the silicon nitride dried powders. The first group includes the types of atomizers, manifolds, and drying chamber configurations. The process parameters fall into the second group and include the following: inlet temperature, atomizing air flow, feed flow rate, drying gas flow rate, outlet temperature, and drying time. Finally, the last group, feedstock parameters, includes many factors such as feed surface tension, feed viscosity, solvent type, solid particle concentration, and additives. Given the large number of factors affecting morphology, particle size and moisture, optimizing the spray drying process is usually achieved by the “trial and error” approach. Nevertheless, some factors such as the effect of a solvent, dispersant, binder, and sintering additives considered in the literature that affect the Si₃N₄ granulation process were reviewed in the work. By summarizing the data available on silicon nitride powder production, the authors attempt to tackle the problem of its emerging demand in science and industry.

This paper deals with the application of statistical analysis in the study of the dependence of the flexural strength of sintered alumina (Al₂O₃) disks on the parameters (nozzle diameter of the printer print head, layer height, and filling pattern) of the fused deposition method (FDM) printing of ceramic–polymer filament containing 60 vol.% alumina and 40 vol.% polylactide. By means of a correlation analysis applied to the results of flexural tests, a linear relationship was found between the thickness of the printed layer and the strength of the sintered specimens. A statistically significant linear relationship was found between the geometric parameters and the weight of both printed ceramic–polymer and sintered ceramic samples, as well as the diameter of the nozzle used in the printing of the workpiece. It was found that the highest strength is achieved with a layer thickness equal to 0.4 mm, and the smallest scatter of mass values and geometric dimensions of ceramic samples is achieved using a nozzle diameter of 0.6 mm. As a result of the conducted research, linear equations allowing the prediction of changes in the geometry and mass of samples after sintering, as well as the strength properties of sintered samples, taking into account the geometry and mass of FDMed samples, were obtained.

Additive manufacturing by selective laser melting (SLM) is generally applicable to glasses while insufficient resistance of the material to thermal shocks due to local laser heating may result in cracking and a high viscosity of glass melt is responsible for incomplete powder consolidation related to residual porosity. The present work shows that preheating up to 350 °C is sufficient to avoid cracking of soda-lime glass. Preheating of quartz glass up to 730 °C considerably decreases the residual porosity, which is explained by acceleration of powder consolidation by the viscous-flow mechanism of glass particles’ coalescence. Variation of the preheating temperature is an effective tool to control consolidation of glass powder and to avoid cracking.

Statistical analysis of mechanical properties of thin-walled samples (~500 microns) obtained by selective laser melting from AlSi10Mg material and subjected to heat treatment for 1 h at temperatures from 260 °C to 440 °C (step of aging temperature change 30 °C) has shown that the maximum strain hardening in the stretching diagram section from yield strength to tensile strength is achieved at the heat treatment temperature equal to 290 °C. At carrying out of correlation analysis, a statistically significant positive correlation between deformation corresponding to yield strength and the sum of heights of the largest protrusions and depths of the largest depressions of the surface roughness profile within the basic length of the sample (Rz) and the full height of the surface roughness profile (Rmax) was established. It was found that the reason for the correlation is the presence of cohesive states between the extreme values of the surface roughness profile that persist along the entire length of the specimen.