International Scientific Journals
of Scientific Technical Union of Mechanical Engineering "Industry 4.0"

The aim of this work is to evaluate the residual stresses in advanced composite ceramic coatings (60wt% Al₂O₃ – 40wt% SiO₂) was produced by thermal spraying coating (flame spraying) on the mild steel substrate (AISI 1050) steel. The bond coat used in this work was AlNi alloy between metallic substrate and advanced composite ceramic coatings which was implemented by flame spraying technique. The thickness of bond coating was (150ϻm) and for composite ceramic coating was (450 ϻm). the residual stresses evaluated by X-Ray diffraction technique were compressive residual stresses ( -62.6099), while by finite element method were compressive residual stresses (-68.491). The percentage of agreement between the residual stresses evaluated by X-Ray diffraction technique and finite element technique was (91.509%).

This work was focused for studying the effect of ablation time on the producing ZnO nanoparticles by Liquid –Phase Pulsed Lase Ablation (LP-PLA) of Zn metal plate in the aqueous environment of cetyl trimethyl ammonium bromide (CTAB) with molarity (10^-2 M) using Q-Switched Nd:YAG pulsed laser has wavelength= 1064 nm, Rep. rate= 10 Hz, Pulse duration =6 ns and laser energy 170 mJ. The effect of ablation time on the optical and structure of ZnO was studied is characterized by UV-visible absorption. UV-visible absorption spectrum has four peaks at 219, 232,242,249 nm for ablation time (5, 10, 15, and 20 min) respectively, our results show that UV–visible spectra show a blue shift in the presence of CTAB with decrease the ablation time and blue shift indicated to get smaller size of nanoparticles. The blue shift in the absorption edge indicates the quantum confinement property of nanoparticles. Also FTIR transmittance spectra of ZnO₂ nanoparticles prepared in these states show a characteristic ZnO absorption at 435–445cm⁻¹.