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Published in Domenico Lombardo, Ke Wang, Advances in Materials Science and Engineering, 2021
Z.X. Zhang, H.F. Tian, F.L. Tantai, H. Liu, W. Wang, J.S. Sun
The melting point of TiC is as high as 3140°C, and it can be precipitated in the molten pool as the non-spontaneous nucleation core of Mo2FeB2, so that the formed ternary boride Mo2FeB2 will be dispersed and distributed. At the same time, TiC and Mo2FeB2 phases formed by in situ reaction can form a pollution-free and weak interface bonding dual ceramic phase, which can effectively improve the strength and toughness of Mo2FeB2-based cermets [6]. The addition of rare earth to the cermet coating can improve the performance of the cermet coating by refining the crystal grains, purifying the molten pool, producing solid solution strengthening and dispersion strengthening, and reducing the dilution of the base material to the coating microstructure. The rare earth modification technology is used in the preparation process of cermet coatings such as laser surface cladding, which can significantly improve the strength and hardness of the coating, enhance the bonding strength of the coating and the substrate, improve the tribological properties of the coating, and improve the service performance of the cermet coating [7]. In this study, Mo powder, ferroboron, iron powder, and Cr powder are used as the main raw materials, and TiC, rare earth, ferro-titanium, and chromium carbide are added respectively to study the influence of TiC and rare earth on the structure and properties of the laser cladding layer. The influence of TiC and rare earth on the quantity and morphology of the hard phase Mo2FeB2 was also studied.
The wear resistance increasing of the deposited coatings of the Ni-Cr-B-Si system by modifying them with composite materials synthesized using the SHS process (Self-propagating high-temperature synthesis)
Published in Welding International, 2019
S.A. Luzan, A.I. Sidashenko, A.S. Luzan
Boron is one of the most efficient and economical microalloying elements in steel. In most cases, the minimum concentration of boron in the metal to obtain a positive result is about one thousandth of a mass fraction of a percent. The uniqueness of boron lies in the fact that with such a low content in steel, it is capable of exerting an effect on its properties, which is equivalent to the action of a much larger amount of such alloying elements as Cr, Mo, Ni, etc. Ferroboron is a traditional material used for boron alloying of steel. Long-term practice of using ferroboron has shown that it is rather difficult to microalloy steel with boron using it. This is due, first of all, to the high reactivity of boron in the steel melt and its high chemical affinity for oxygen and nitrogen. In addition, in most cases, it is required to provide an extremely low concentration of dissolved boron in the metal. Therefore, when obtaining a composite material, titanium diboride will be synthesized (2).