Study of the correlation between mechanical properties and erosion behavior of CrN-based nanostructured coating applied by PVD technique

Study of the correlation between mechanical properties and erosion behavior of CrN-based nanostructured coating applied by PVD technique


Study of the correlation between mechanical properties and erosion behavior of CrN-based nanostructured coating applied by PVD technique

نوع: Type: پایان نامه

مقطع: Segment: کارشناسی ارشد

عنوان: Title: Study of the correlation between mechanical properties and erosion behavior of CrN-based nanostructured coating applied by PVD technique

ارائه دهنده: Provider: Nafiseh Fereshteh Saniee

اساتید راهنما: Supervisors: Dr. Hassan Elmkhah- Dr Meisam Nouri

اساتید مشاور: Advisory Professors:

اساتید ممتحن یا داور: Examining professors or referees: Dr. Hamid Esfahanie- Dr. Mohsen Sheikhie

زمان و تاریخ ارائه: Time and date of presentation: 2022/9/6

مکان ارائه: Place of presentation: room 200

چکیده: Abstract: One of the current challenges for industrial components is surface degradation due to erosion. Surface engineering is an excellent selection to improve the erosion resistance of materials. In this study, CrN, CrTiN, and CrTiSiN coatings were applied on the 410 martensite steel substrate using physical vapor deposition method to increase its erosion resistance. X-Ray diffraction was used to identify various phases. Moreover, scanning electron microscope (SEM) and field emission scanning electron microscope (FESEM) were employed to evaluate morphologies of coating surface and cross-section. Mechanical properties of the coatings were obtained utilizing nano-indention test. To investigate the erosion behavior of samples, SiO2 solid particle erosion tests were conducted at 30o and 90o angles by gas jet method. To evaluate the wear resistance of various coatings, several pin on disk experiments were also carried out using a pin made of Al2O3. The hardness of the substrate and CrN, CrTiN and CrTiSiN coatings were respectively found to be 4.2, 17.84, 20.28 and 23.52 GPa. Moreover, their Young's moduli were correspondingly obtained as 264.35, 245.12, 269.69 and 403.03 GPa. The erosion test results for CrTiN coating showed 70% and 19.5% decrease in the mass loss, respectively at 30 and 90 angles, compared with the substrate. To examine the relationship between mechanical properties and related erosion behavior, H/E and H3/E2 ratios were employed. Experimental findings revealed that the substrate presented the lowest H3/E2, i.e. 0.001 GPa, and the highest erosion rate, namely 3.25. On the other hand, among different samples, the CrTiN coating exhibited the maximum H3/E2 (i.e. 0.117 GPa) and minimum erosion rate (0.45). With this regard, a second-order polynomial equation was derived to correlate the erosion behavior of material to its H/E and H3/E2 ratios. This equation can play an important role for interpreting the erosion behavior of materials. Furthermore, evaluations of wear behavior indicated lower mass loss of 1.10, 1.38, and 2.16 mg for CrN, CrTiN, and CrTiSiN coatings, in comparison with the substrate. Therefore, it can be claimed that the nitride coatings considered in this research have improved both the wear behavior and the erosion resistance. A direct relation was observed between the trends of the wear rates of specimens and their hardness. In addition, for all types of coatings excepting CrTiSiN, the trends of wear rates were reasonable and expected, based on the H/E and H3/E2 ratios. This exception could be due to dissimilar mechanism of CrTiSiN coating. Finally, it should be emphasized that although H/E and H3/E2 ratios are strong criteria for estimation of erosion and wear behaviors of different coatings, paying necessary attentions to mechanisms of these two phenomena is also essential.

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