Structure, Mechanical Properties, and Oxidation Resistance of MoSi2, MoSiB, and MoSiB/SiBC Coatings

• Published in: Russian journal of non-ferrous metals 2018-11, Vol.59 (6), p.698-708
• Main Authors: Kiryukhantsev-Korneev, Ph. V., Potanin, A. Yu
• Format: Article
• Language: English
• Subjects: Chemistry and Materials Science; Elastic recovery; Elastoplasticity; Hardness; Magnetron sputtering; Materials Science; Mechanical properties; Metallic Materials; Modulus of elasticity; Molybdenum disilicides; Monolayers; Multilayers; Nanoindentation; Nanostructured Materials and Functional Coatings; Optical emission spectroscopy; Optical properties; Oxidation; Oxidation resistance; Protective coatings; Scanning electron microscopy; Silicon dioxide; Thermal stability; X-ray diffraction
• ISSN: 1067-8212; 1934-970X
• DOI: 10.3103/S106782121806010X

Single-layer MoSi 2 , MoSiB, and multilayer MoSiB/SiBC coatings are fabricated by magnetron sputtering. Coating structures are investigated using X-ray diffraction, a scanning electron microscopy, and glow-discharge optical emission spectroscopy. Mechanical properties of coatings are determined by nanoindentation. The thermal stability of coatings is studied in a temperature range of 600–1200°C and oxidation resistance is studied upon heating to 1500°C. It is established that single-layer MoSiB coatings possess a hardness of 27 GPa, elasticity modulus of 390 GPa, and elastic recovery of 48%. They can also resist oxidation up to 1500°C inclusively, which is caused by the formation of the SiO 2 -based protective film on their surface. The MoSi 2 coatings can have hardness comparable to the hardness of MoSiB coatings, but they are somewhat worse than them in regards to oxidation resistance. Multilayer MoSiB/SiBC coatings have hardness 23–27 GPa and oxidation resistance restricted by 1500°C, but they herewith have higher elastoplastic properties when compared with MoSiB.