Print ISSN: 1681-6900

Online ISSN: 2412-0758

Keywords : Taguchi design

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 2A, Pages 180-188
DOI: 10.30684/etj.v39i2A.1570

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.

Study of some Mechanical Properties and Erosive Behavior by Taguchi Method for Hybrid Nano Composites

Reem Mohammed

Engineering and Technology Journal, 2018, Volume 36, Issue 4A, Pages 471-479
DOI: 10.30684/etj.36.4A.15

The aim of this research is study the effect Nano TiO2 powder on impact strength, fracture toughness, hardness shore (D) and erosive wear behavior of polymer composites materials are prepared by simple hand lay-up technique. The specimens was prepared by adding (1%, 2%,3%,4%,5% & 6%) weight fraction of nano powder (TiO3) has average size of (16 nm) to unsaturated polyester resin reinforcement with (5%) weight fraction of carbon fiber. The value of erosive wear rate for polymer composite materials can be obtaining after (15 hours) and under effect various parameters such as impingement angle (30 º, 45 º, 60 º, 90º), erodent size of sand silica (300, 400 ,500,600 μm) and stand-of distance (17, 19, 21,23 cm). Also in this research study effect of parameters on erosive wear rate by the used of Taguchi orthogonal arrays L16. The results show the maximum value of impact strength , fracture toughness and hardness (shore D) was founded at specimen (89% UP +5% C.F+6% TiO2) also this specimen has the best resistance to erosive wear rate under parameters (23cm stand- off distance , 300 μm erodent size of sand silica , 60 º impact angle) than other specimens. From analysis of variance (ANOVA) the filler content and impingement angle factor have more effect on erosive rate while the stand-off distance and erodent size of sand less effect on erosive wear rate .

Investigation Nano coating for Corrosion Protection of Petroleum Pipeline Steel Type A106 Grade B; Theoretical and Practical Study in Iraqi Petroleum Sector

M. J. Kadhim; K. A. Sukkar; A. S. Abbas; N. H. Obaeed

Engineering and Technology Journal, 2017, Volume 35, Issue 10, Pages 1042-1051
DOI: 10.30684/etj.35.10A.11

In the present investigation, titania (TiO2) nano-thin films were deposited on steel type A106-B, by using the Pulse Laser Deposition (PLD) technique to obtain passive layers of nano-coating. Electrochemical methods (Tafel completion) are used for study corrosion behavior of steel coating. The A106-B specimens were evaluated in 3.5 wt. % NaCl aqueous solution by using polarization technique with pH adjustment to 4.0 in order to determine the corrosion rate. The samples of TiO2 thin films were characterized by SEM, AFM, XRD, and FTIR. The input parameters were substrate temperature (100, 200 and 300) ’0C’, number of pulse (300, 400 and 500) and fluencies energy (800, 900 and 1000) mJ/cm2, have been investigated to detect their impact on corrosion reduction rate using Taguchi methodology orthogonal array and Analysis of Variance (ANOVA).The ANOVA results indicates that number of shoots pulse significantly affecting the corrosion rate in PLD technique, which is highest among the contributions of the other parameters which is (58.03%) about three times of the fluencies energy (19.12%).The results show that the TiO2 deposition on steels offers an excellent corrosion resistance about 99 times as compared with uncoated steel. The optimum conditions to minimum values corrosion rate are: temperature of 300ºC, number of laser pulses at 300, and fluencies energy equal to 1000 mJ/cm2. Finally the optimal parameters that was used to predict the conclusions were (98.6) to the response of corrosion rate.