Print ISSN: 1681-6900

Online ISSN: 2412-0758

Author : A. Hashim, Fadhil

Effect of Laser Treatment on the Surface Roughness of Multilayer Plasma Sprayed Thermal Barrier Coating System

Mais A. Habeeb; Mohammed J. Kadhim; Fadhil A. Hashim; Maryam A. bash

Engineering and Technology Journal, 2021, Volume 39, Issue 2, Pages 180-188
DOI: 10.30684/etj.2021.168102

Thermal barrier coatings (TBCs) are used in advanced engines working at higher temperatures. Higher efficiency and performance of gas turbine engines will require careful selection of TBCs. In this study, Ni22Cr10Al1.0Y (Amdry 9625) bond coat and two types of top coat including ceria stabilized zirconia (CSZ) ZrO2-24CeO2-2.5Y2O3) and yttria stabilized zirconia (YSZ) ZrO2-8Y2O3 were deposited on IN 625 by air
plasma spraying (APS). The thickness of the duplex ceramic coat based on zirconia was in the range between 350 to 400 μm. The effect of high power Yb:YAG solid state laser at different laser parameters on feature, microstructure and roughness of plasma sprayed and laser sealed coating of multilayer ceria stabilized zirconia/ yttria stabilized zirconia was investigated. Surface roughness has been reduced significantly after laser sealing. The effect of laser process parameters carried out using Taguchi’s L16 orthogonal array design. Minimum roughness can be obtained at moderate power density and longer interaction time with sufficient specific energy to produce complete melting of coating. Characterization and analysis of results was achieved by employing scanning electron microscopy (SEM) , (EDS) and image J analysis. It was found from the results, there were significant improvements in the performance of plasma sprayed coatings after laser sealing due to the reduction of surface coating defects.

Processing and Properties of ZA-27 Alloy Metal Matrix Hybrid Composite Reinforced with Nanonitrides

Fadhil A. Hashim; Niveen J. Abdulkader; Kateralnada F. Hisham

Engineering and Technology Journal, 2020, Volume 38, Issue 1, Pages 57-64
DOI: 10.30684/etj.2021.168175

In general, internal vibrations within the pipelines caused by fluids being passing through a pipeline system can cause. These pipeline system can damage by the sudden amplified vibrations that were not considered at the design of the system, and flow induced vibrations resonate with the pipes natural frequency. Therefore, it is important to predict and identify the pipeline system vibrations during its lifetime. In this study by using MATLAB code as a CFD solver, it studied the forced and free vibrations caused by fluid flows at Reynolds number ranged as 0 < Re < 2500 for laminar flow and ranged as 104 < Re < 105 for turbulent flow. The working fluid has chosen as of (Al2O3, TiO2, SiO2 and water) with different nanoparticle volume fraction of (0 to 2% vol.). These fluids flow in simply supported pipe with different lengths and diameters. The results presented the effect of pipe and fluid parameter upon the fluid critical velocity and fundamental natural frequencies. The results showed that the pipe natural frequency increased with increasing with decreasing the pipe length and diameter. In addition, it showed that the pipe natural frequency decreased when using the different nanoparticle depressed in the water and with increasing the volume fraction.