OBRABOTKAMETALLOV MATERIAL SCIENCE Vol. 25 No. 3 2023 a b Fig. 2. Microstructure of borides in the coatings obtained by surfacing the powder mixtures with different CrB content: a – 5 % CrB; b – 10 % CrB borides were revealed in the structure, which presumably prevent the formation of an oriented structure during the crystallization of the melt pool. Fig. 2 shows the microstructure of the coatings obtained by surfacing the mixtures with 5 % and 10 % CrB. The appending of 5 % CrB led to the formation of a coating with a hypoeutectic structure represented by a metal matrix and a fine lamellar eutectic located in the interdendritic regions. The structure of the coatings obtained from mixtures containing 10 % CrB is hypereutectic. In the coating, primary borides with lamellar eutectic between them were formed (fig. 2b). Fig. 3 shows the elemental distribution maps from the coating obtained with the appending of 10 % CrB. The boron distribution map is not provided because of the low accuracy of the determination of light elements by the energy dispersive analysis. It can be seen in Fig. 3 that the chromium concentration is maximum in the primary boride crystals and eutectic borides and decreases in the metal matrix. Manganese and iron are distributed more evenly and can be found in both the borides and the matrix, while nickel and cobalt are predominantly present in the matrix. a b c Fig. 3. Distribution of elements in the structure of the coating obtained by surfacing the powder mixture with 10 % CrB: a – microstructure of the analyzed region; b – Cr; c – Mn; d – Fe; e – Co; f – Ni d e f
RkJQdWJsaXNoZXIy MTk0ODM1