Processing-structure-property relationships in electron beam physical vapor deposited yttria stabilized zirconia coatings

Abstract

The physical and mechanical properties of yttria stabilized zirconia ͑YSZ͒ coatings deposited by the electron beam physical vapor deposition technique have been investigated by varying the key process variables such as vapor incidence angle and sample rotation speed. The tetragonal zirconia coatings formed under varying process conditions employed were found to have widely different surface and cross-sectional morphologies. The porosity, phase composition, planar orientation, hardness, adhesion, and surface residual stresses in the coated specimens were comprehensively evaluated to develop a correlation with the process variables. Under transverse scratch test conditions, the YSZ coatings exhibited two different crack formation modes, depending on the magnitude of residual stress. The influence of processing conditions on the coating deposition rate, column orientation angle, and adhesion strength has been established. Key relationships between porosity, hardness, and adhesion are also presented.

Thermal barrier coating deposition by rarefied gas jet assisted processes: Simulations of deposition on a stationary airfoil

“…Thermal barrier coatings are often deposited on gas turbine airfoils using an electron beam-physical vapor deposition (EB-PVD) process. 1,13,14 In the traditional EB-PVD method, an intense electron beam is used to melt and evaporate a ceramic source material. The evaporated molecules travel to, and condense on the airfoil, in a high vacuum in which few gas phase collisions occur.…”

Functionalization methods of carbon fibers – an overview

“…This is largely due to the fact that sputtering and evaporation techniques are line-of-sight processes, which means that the deposited material is carried about the area from a source to the matrix [31]. Facing occurrence of the angle-of-incidence effect on the matrix surface, the coating material is mainly deposited in the areas in the direct field of the working source [32]. The result of it is the formation of various types of defects (nodal defects, holes, pores), which in the PVD process literature are referred as growth defects (to emphasize that they are the result of slow growth) [33].…”

Phase evolution of EBPVD coated ceria-zirconia nanostructure and its impact on high temperature oxidation of AISI 304

“…EBPVD is an atom-by-atom evaporation technique and the processing parameters such as deposition rate, substrate temperature, vapour incidence angle and substrate rotation may influence the phase formation. In the present work, the deposition rate (0.2 nm/s), substrate temperature (373 K) and rotational speed (20 rpm) are kept low and constant for all the coatings and hence, the kinetic energy of deposited atom is low so that the atoms are stabilized to metastable tetragonal phase for C50Z50, C25Z75 and Z100 [35,36]. The presence of intense peaks from the substrate posed difficulty in the quantitative analysis of the phases.…”