چكيده به لاتين
Seeking to take advantage of protective coatings in gas turbine components, a systematic approach is necessary to assess the life of these coatings. The aim of this paper is firstly to investigate of erosion life of coated and uncoated components, and then, to present a comprehensive application for assessment of the erosion life of the components based on previous international efforts. In order to reduce the computational costs and time, this study presents a three-dimensional finite element model using representative volume element (RVE) technique for simulation of multiple solid particles impact on a Ti-6Al-4V alloy. After verification of the present FE model, based on this model, the best architecture of Titanium-Nitride (TiN) based coatings deposited on Ti-6Al-4V alloy is numerically determined. At first, characteristics of the best monolayer TiN coating are obtained to use as a reference for multilayer configurations. Then, effects of thickness, Young’s modulus, TiAlN layers and Ti soft layer on erosion resistance of the coatings are studied to optimize architecture of multilayer coatings. Finally, the optimized coating is deposited on Ti-6Al-4V alloy by physical vapor deposition (PVD) process and erosion behavior of the coated and uncoated alloy is experimentally studied. Numerical results show that TiN/Ti/TiAlN coating is the best erosion-resistant coating compared to the other configurations of this study. It is made of a TiAlN bottom layer with thickness of 9 microns and Young’s modulus of 526 GPa, a Ti soft interlayer with a thickness of 0.8 microns and a TiN top layer with thickness of 1 micron and Young’s modulus of 300 GPa. Experimental results show that maximum erosion rate was occurred at impact angle of 45 degrees for the uncoated alloy and at angle of 90 degrees for the coated alloy. Also, an average 2.7 times improvement is experimentally obtained in relative erosion resistance for the coated alloy compared to the uncoated one.
