Abstract
Powder Mo&O2 has an important role in the production of coatings with increased resistance to slide in conditions without the use of lubricants. Mo&O2 coatings have the low coefficient of friction and good abrasion characteristics in mechanical stresses. For the purpose of producing coatings of high hardness, Mo&O2 powder is plasma deposited with optimal parameters. The surface shape of oxide powder particles and the coating fracture surface are analysed by SEM, and the microstructure of layers is examined by light microscopy. The coating microstructure consists of Mo lamellae and MoO3 and MoO2 primary oxide thin films, which surround the Mo lamellae. The analysis of the obtained results showed that the Mo&O2 coating layers with the diffusion oxidized Mo particles have such a structure and mechanical characteristics which enable its application in working tools under the conditions of wear and sliding friction without lubricants.
Highlights
The Mo&O2 coating resistance to wear depends on the oxygen content and the applied kind of technological process of coating production (Mrdak, et al, 2005, pp.235-239), (Salhi, et al, 2005, pp.145– 150)
The surface shape of oxide powder particles and the coating fracture surface are analysed by surface recorded by electron microscope (SEM), and the microstructure of layers is examined by light microscopy
The analysis of the obtained results showed that the Mo&O2 coating layers with the diffusion oxidized Mo particles have such a structure and mechanical characteristics which enable its application in working tools under the conditions of wear and sliding friction without lubricants
Summary
The Mo&O2 coating resistance to wear depends on the oxygen content and the applied kind of technological process of coating production (Mrdak, et al, 2005, pp.235-239), (Salhi, et al, 2005, pp.145 150). Molybdenum powders containing oxygen Mo&O2 can attain high hardness values. After the production of Mo&O2 coatings, the layers have sufficient concentration of oxygen which gives to oxides high hardness the values of which exceed 1000HV. Deposited coatings can increase fatigue strength to friction up to 120% in working tool surfaces, preventing loss of the material by friction. The authors (Chen, et al, 2007, pp.21322138), (Yongqing, et al, 2000, pp.231-245) found that Mo lamellae and MoO2 and MoO3 primary oxides from powder are present in the Mo&O2 coating. The best structure is found in coatings where oxide films are continuously arranged along the coating and act as a lubricant while preventing metal contact and maintain a low coefficient of friction. Tests of the Mo&O2 coating to wear determined that MoO2 oxide in the coating reduces the coefficient of friction under 0:15, and MoO3 oxide to the values in the range of 0.1 to 0.12 which is quite stable (Lyo, et al, 2003, pp.413-421), (Solak, et al, 2003, pp.713-719), (Suszko, et al, 2005, pp.319-324)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
