Features of Synthesizing Ceramic Composites Discretely Reinforced by Carbon Fibers and SiC Nanowires Formed in situ in the Combustion Wave

Russian Journal of Non-Ferrous Metals - A new method is proposed for the engineering of SiC-based ceramic-matrix composite materials strengthened by discrete carbon fibers and single-crystal...     

Structure and properties of tribological coatings in Cu-B system

The effect of B additions on the structure and mechanical and tribological properties of Cu coatings produced by magnetron sputtering from mosaic targets has been investigated. It has been shown that the introduction of B results in structure refinement of the coatings. The hardness, elasticity modulus, elastic recovery, and plasticity index of Cu-B coatings have been determined. It has been established that the introduction of 7–15 at % of boron favors a decrease in the coefficient of friction and reduced wear. It has been shown that high tribological characteristics of coatings in the Cu-B system are connected with the formation of solid H₃BO₃ lubrication on the coating surface.     

Self-propagating high-temperature synthesis of advanced ceramics in the Mo–Si–B system: Kinetics and mechanism of combustion and structure formation

The goal of this work is to investigate the combustion mechanisms of reactions in the Mo–Si–B system and to obtain ceramic materials using the SHS method. It is concluded that the following processes are defined by the SHS for Si-rich Mo–Si–B compositions: silicon melting, its spreading over the surfaces of the solid Mo and B particles, followed by B dissolution in the melt, and formation of intermediate Mo₃Si-phase film. The subsequent diffusion of silicon into molybdenum results in the formation of MoSi₂ grains and molybdenum boride phase forms due to the diffusion of molybdenum into B-rich melt. The formation of MoB phase for B-rich compositions may occur via gas-phase mass transfer of MoO₃ gaseous species to boron particles. The stages of chemical interaction in the combustion wave are also investigated. The obtained results indicate the possibility of both parallel and consecutive reactions to form molybdenum silicide and molybdenum boride phases. Thus the progression of combustion process may occur through the merging reaction fronts regime and splitting reaction fronts regime. Molybdenum silicide formation leads the combustion wave propagation during the splitting regime, while the molybdenum boride phase appears later. Finally, targets for magnetron sputtering of promising multi-phase Mo–Si–B coatings are synthesised by forced SHS compaction method.     

Structure,Mechanical Properties,and Oxidation Resistance of ZrB2, ZrSiB,and ZrSiB/SiBC Coatings

Protection of Metals and Physical Chemistry of Surfaces - ZrB2, ZrSiB single-layer coatings, and ZrSiB/SiBC multilayer coatings have been fabricated by magnetron sputtering. The coating structure...     

Influence of Ti and TiH2 Additives on the Structure and Properties of Copper Alloys for Diamond Cutting Tools

Russian Journal of Non-Ferrous Metals - The influence of titanium and titanium hydride additives on the structure, mechanical properties, and wear resistance of copper alloys intended for use as a...