The study of high temperature tribological behavior of CrN-based nano-multilayer coating deposited via PVD method on Ti6Al4V alloy

نوع: Type: Thesis

مقطع: Segment: masters

عنوان: Title: The study of high temperature tribological behavior of CrN-based nano-multilayer coating deposited via PVD method on Ti6Al4V alloy

ارائه دهنده: Provider: alireza maleki

اساتید راهنما: Supervisors: dr.nouri - dr elmkhah

اساتید مشاور: Advisory Professors:

اساتید ممتحن یا داور: Examining professors or referees: dr.sheikhi - dr.pak

زمان و تاریخ ارائه: Time and date of presentation: 2025

مکان ارائه: Place of presentation: 25

چکیده: Abstract: In recent years, surface engineering has gained considerable importance as an effective approach to improve the performance of industrial components, especially in gas turbine engines, where most degradation mechanisms initiate at the surface. Although titanium alloys possess excellent specific strength and corrosion resistance, their resistance to wear and solid particle erosion is relatively low. In this study, a nanolayered CrN/CrAlN coating was deposited on Ti-6Al-4V alloy using cathodic arc physical vapor deposition (PVD) to enhance surface and tribological properties. The performance of the coating was evaluated through pin-on-disk wear tests up to 700 °C and solid particle erosion tests up to 500 °C. Complementary analyses including microhardness, adhesion (Rockwell C and VDI-3198), X-ray diffraction (XRD), and electron microscopy (SEM, FESEM) were employed to assess the structural and mechanical behavior. The results revealed a uniform multilayer structure with strong adhesion to the substrate. The wear rate decreased at intermediate temperatures and increased at higher temperatures due to oxidation. In erosion tests, the coated samples showed significantly lower mass loss compared to the uncoated substrate, confirming a remarkable improvement in erosion resistance. Morphological observations indicated the formation of stable Al-oxide layers and inhibition of crack propagation. Overall, the CrN/CrAlN multilayer coating effectively improved wear, erosion, and adhesion performance at elevated temperatures, making it a promising candidate for extending the service life of titanium alloy components in aerospace and power generation industries.