Print ISSN: 1681-6900

Online ISSN: 2412-0758

Keywords : Coating

Experimental Investigation of Surface Roughness Using Uncoated and Coated Tungsten Carbide Cutting Tool in Turning Operation

Frzdaq N. Thamer; Ali Abbar; Farhad. M. Othman

Engineering and Technology Journal, 2021, Volume 39, Issue 5A, Pages 768-778
DOI: 10.30684/etj.v39i5A.1887

The cutting process is an important process of industrialization. It is requisite to using advantage quality cutting tools in order to preserve the type of product. Coating on the cutting tool has a substantial effect in terms of mechanical properties and the end results of the product. The cutting tool can be manufactured in various material types, but today's cemented tungsten carbide is the most commonly used material in the tool industry because its properties comply with manufacturers' requirements. This study investigates the impact of an Al2O3 coated cutting tool relative to an uncoated cutting tool on the dry cutting process. Different parameters are used in the cutting process when cutting the metal. The cutting parameters used are feed rate and cutting speed, An analysis of the effects of these parameters on the surface roughness. In this analysis, the surface roughness are measured for components turned from steel1040, The L9 Taguchi orthogonal arrays and analyses of variance (ANOVA) was employed to analyze the influence of these parameters. In the case of (uncoated, Al2O3 coated tool), the better surface roughness (SR) with used feed rate (0.05 mm / rev) and cutting speed (140 m/min) where the roughness value was (0.81μm) and (0.78μm) Respectively. The results of this study indicate that the ideal parameters combination for the better surface finish was high cutting speed and low feed rate.

Optimizing of Coating Layers Parameters of (Nano Hydroxyapatite/TiO2 NPs) on Nitinol SMAs by Electrophoretic Deposition

Riyam R. Rawdan; Makarim H. Abdulkareem; Ali Mustafa

Engineering and Technology Journal, 2020, Volume 38, Issue 4A, Pages 530-544
DOI: 10.30684/etj.v38i4A.577

This study aims to obtain the optimal variable for depositing (HA, TiO2 and Composite) Nanomaterial on NiTi SMAs. Taguchi approach (with L9 array) was used to obtain the optimal conditions for coating produced by Electrophoretic deposition (EPD) techniques. The deposition process was done in different conditions (voltage, time, concentration and degree of grinding). Voltages were used (20, 40 and 60) volts, the time is (2, 4 and 6) min, the degree of the surface roughness (180, 500 and 1200) μm while the concentration of HA and TiO2 are (2, 4, and 6) g/L for each one. Chitosan (biopolymer) was used as binder material to the ceramic materials. The result of the Taguchi approach detected that the best conditions of HA layer are (20 V, 4 min, 2%C and the degree of surface 180), TiO2 is (20 V, 4 min, 4%C and the degree of surface 180) and composite layer is (60 V, 4 min, 4%C and the degree of surface 180). Solutions stability was measured by utilizing Zeta potential tests; which clarified good stability for all of them. Optical microscope and scanning electron microscopy were used to characterize and study the surface of the coating layers. The bonding adhesion was measured using a tape test in order to evaluate the adhesion bonding between the coating and substrate. It found that the percentage of removal coating area for samples were (8.8%for HA, 4.9% for TiO2 and 6.9% of the composite layer.

Synthesized Cu (In, Ga) Se2 (CIGS) thin films and implementation as the active light absorbing material in photovoltaic devices (PVs)

Omar A. Ali; Wasan R. Saleh; Vikas V. Reddy; Jackson Stolle; Cao Meng; Brian A. Korgel

Engineering and Technology Journal, 2015, Volume 33, Issue 9, Pages 1753-1760

This review article summarizes our research focused on Cu(In, Ga)Se2 (CIGS) nanocrystals, including their synthesis and implementation as the active light absorbing material in photovoltaic devices (PVs). CIGS thin films were prepared by arrested precipitation from molecular precursors consisting of CuCl, InCl3, GaCl3 and Se metal onto Mo/soda-lime glass (SLG) substrates. We have sought to use CIGS nanocrystals synthesized with the desired stoichiometry to deposit PV device layers without high temperature processing. This approach, using spray deposition of the CIGS light absorber layers, without high temperature selenization, has enabled up to 1.5 % power conversion efficiency under AM 1.5 solar illumination. The composition and morphology of CIGS thin films were studied using energy dispersive spectroscopy (EDS) and scanning electron microscopy (SEM), respectively. X-ray diffraction (XRD) studies show that the structural formation of CIGS chalcopyrite structure.

Isothermal Oxidation of Simple and Pt-Modified Diffusion Coating on Inconel Alloy 600 In Water Vapor

Khalil; Al- Hatab; Al- Alqawie; Hussein; Ahmed Ali; Moosa

Engineering and Technology Journal, 2009, Volume 27, Issue 2, Pages 288-299

In this work the oxidation behavior of both inconel alloy 600 and coated system
(Pt-modified aluminide coating) was investigated in pure water vapor H2O in the
temperature range 700 - 900 ºC. The platinum was deposited by electrochemical
method. Pt-modified aluminide coating was applied to inconel alloy 600 by using singlestep
high activity pack cementation method. The weight gain measurements indicate
that the oxidation kinetic is parabolic for uncoated and coated alloy. At temperatures
below 900 ºC the inconel alloy 600 is less aggravated in water vapor environments
because it is a chromia former alloy. At 700 ºC, water vapor does not have a significant
effect on the spalling of oxide scales. At 900 ºC, water vapor causes spalling of the
oxide scales during isothermal oxidation of inconel alloy 600. Therefore, it is concluded
that this alloy should not be used above 900 ºC in water vapor environments. Large
voids were found at the oxide scales-substrate interface and at grains or at grain
boundaries due to the chromium outward diffusion toward the oxide scales.
At 900 ºC, the parabolic rate constant (kp) of the coated system was one order of
magnitude lower than that for the uncoated alloy. It was concluded that, water vapor
exhibit little effect on the Pt-modified aluminide coating. Oxide phases that formed on
coated system are: Al2O3, NiAl2O4, Cr2O3, and NiFe2O4.