Cracking of nickel superalloys with a high content of ????’-phase remains an unresolved problem, including in technologies for repairing gas turbine engines blades. Laser cladding is a method of material deposition used to repair parts exposed to aggressive environment and surface wear. Cladding parameters have a high influence on cracking susceptibility nickel superalloys. Alloy ZhS32 has a high propensity for hot cracking when exposed to laser radiation. In this work, the study of the structural and phase features of ZhS32 alloy was carried out. A high tendency to form segregation of refractory elements and carbides in the intergranular areas was found. The features of the structure and phase composition of the material for different cladding parameters were studied. The main contribution of technological parameters to the formation of cracks is shown.

Modern methods and technologies for the creation and processing of materials provide great opportunities for research. This work is devoted to the study of the causes of hot cracks, as well as the application of an analytical method for assessing the occurrence of hot cracks in high-temperature nickel alloys ZhS32, ZhS6U, ZhS6K, Rene 80, Rene 41, processed by laser powder cladding. In the course of the work, the process of the influence of a heat source on samples was modeled, an analysis of thermal fields and isotherms was performed, on the basis of which an analytical method was developed for finding the criterion for the pressure drop along the crystallization front in different modes and grades of alloys, to assess the tendency to form hot cracks in high-temperature nickel alloys.

Features of microstructure, mechanical properties, and cracking behaviour of the René 80-type superalloy manufactured by laser-based directed energy deposition (DED-LB) have been investigated. Different cracking behaviours were observed in two thin walls fabricated by DED-LB under different conditions. The defect-free thin wall was produced at low power and scanning speed, while increasing energy input during the process led to intensive cracking. Two types of cracks that developed in the René 80-type superalloy were identified: solidification hot cracking and ductility-dip cracking (DDC), caused by σ-phase particles. It was found that transition from an equiaxed structure to a columnar one increased the susceptibility to crack propagation.

For this work, the behavior of the ZhS6K alloy (Russian grade) in the process of direct laser deposition was investigated. Two samples, a “small” one (40 × 10 × 10 mm³) and “large” one (80 × 16 × 16 mm³), were fabricated with direct laser deposition. In both samples, the typical dual-phase γ/γ’ microstructure with cuboidal shape of the γ’ precipitates was observed. Both specimens revealed a similar tendency to continuous increasing in hardness from the bottom to the top associated with the refinement of γ’ precipitates. The “small” sample was essentially crack-free, while the “large” one underwent extensive cracking. The possible effects of various factors, including thermal history, size, and shape of the gamma grains, on cracking behavior were discussed.

Multilayer ceramic capacitors (MLCC) have wide application in electronic due to its electrical characteristics: low equivalent series resistance (ESR) and high volume efficiency. One of the MLCC manufacturing problems is the choice of composition for the end pastes. The experimental results of the termination pastes composition influence on the quality high-voltage MLCC investigation are presented. The causes of the defects appearance in the termination are determined, the composition of the termination paste, which ensures the quality contact of the internal electrode with the external, is proposed.