Table of content

Iraqi journal of mechanical and material engineering

المجلة العراقية للهندسة الميكانيكية وهندسة المواد

ISSN: 20761819
Publisher: Babylon University
Faculty: Engineering
Language: Arabic and English

This journal is Open Access

About

Iraqi journal for mechanical and material engineering is a refereed scientific journal published quarterly by the engineering college/ university of Babylon. It deals with high quality researches in fields of mechanical and material engineering.

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Journal E-mail:
j.mec_mat_eng@yahoo.com
Babylon university/Babylon/Iraq P.O.Box(4)
Tel:++96430245387.(1155)

Table of content: 2018 volume:18 issue:1

Article
INVESTIGATION CORROSION BEHAVIOUR OF DUCTILE CAST IRON WELD JOINT IN SEA WATER
التحقيق من سلوك التاكل لملحومات سبائك الحديد الطرية في ماء البحر

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Abstract

Manual metal-arc welding was carried out for ductile cast iron under welding conditions of (90) A DC current (DCEN) and 20 volts. Welding wire type E- Ni -Fe- CI in diameter of 3.2mm was used and travel speed of 7 inch /min and welded through two passes. The weld joined are examined using X-ray radiography, broken down joint are excepted. Corrosion specimens prepared from free defects joints having measurements of (15*15*3) mm agreeing to ASTM G71-31. Then Optical microscopy was employed to detect the welded joint microstructure and base metal. Micro hardness was implemented using Vickers test. Corrosion examinations are conducted using electrochemical potential state chamber in equipped (sea water 3.5% NaCl),Corrosion examination is achieved using potentiostatic polarization dimensions in saltwater 3.5%NaCl at potential scan rate (+100-100 mv/sec) to estimate corrosion parameters by extrapolating. The corrosion rate was calculated by Tafel equation. The results of corrosion rate can be predicted using a mathematical model using data achieved from practical method and compare these results with the theoretical one, results show that corrosion rate for welded joint is more than the base metal because of the change in metal microstructure during welding process.


Article
EFFECT OF LUBRICANTS CONTAINING DIFFERENT NANO-PARTICLES ON THE PERFORMANCE OF WORN JOURNAL BEARINGS
تأثير الزيوت الحاوية على دقائق نانوية على تصحيح تأثير البلى في المساند المقعدية الاسطوانية

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The present work deals with the isothermal analysis of worn journal bearing lubricated with Nano-lubricants. The bearing wear affect the oil film thickness and causes a decrease in load carrying capacity of the journal bearing. On the other hand, many works show that the addition of Nano- particles to the oil enhances its viscosity. The main goal of the present work is to investigate the ability of the Nano-lubricant to correct the wear effect on the performance of such bearings. The modified Reynolds equation was solved using finite difference technique to obtain the pressure distribution in the clearance gap of the worn journal bearing. Dufran's model was used to include the effect of wear on the thickness of the oil film. The effect of adding three different types of Nano-particles namely, Dimond, CuO and TiO2 to the base oil has been investigated. Bearing static characteristics in terms of load capacity, friction force, end leakage and power loss for different eccentricity ratios have been investigated. The mathematical model has been validated for the pressure results obtained in the present work with that obtained by other workers and the results found to be in a good agreement. The results obtained in the present work show that the load carrying capacity enhances by about40%, 9% and 3% for the bearing with wear depth parameter of 0.4, eccentricity ratio of 0.7 lubricated with oil containing TiO2, CuO and Dimond Nano-particles respectively in comparison with pure oil lubricated bearing.


Article
INVESTIGATION OF FLOW FIELD OVER POST FLOW MODEL WITH THE AID OF ePIV SYSTEM
التحقق من حقل الجريان المار فوق نموذج لعمود جريان باستخدام نظام تصوير سرعة الجسيمات التعليمي

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Abstract

Post flow model was used in the present study as an insert model for the interactive flow study innovative device namely called ePIV. The separation of the flow and its subsequent reattachment to a solid surface occurs in many systems, and is of practical as well as of theoretical interest. Three different values for the upstream velocity were selected in the present work within the range (14, 24, and 32 mms) and two set of figures were observed for every value of upstream velocity. First set for velocity vector plots and shaded color plot while the second is for picture frames captured for the purpose of ePIV system software. It was found that ePIV system can be used in diverse educational settings because of its effectiveness as an educational tool, high-tech appeal, compact size, low cost and safety. Also, It was concluded that the sudden appearance for the post height result in a vortex spot that lead to an adverse pressure gradient concentrate the majority of high bulk velocity magnitude at the upper half of the post flow model height.


Article
EXPERIMENTAL AND NUMERICAL INVESTIGATION OF METASTABLE FLOW OF REFRIGERANT R-22 THROUGH CAPILLARY TUBE
التحقيق العملي والنظري للجريان غير المستقر لمائع التبريد R-22 خلال الانبوب الشعري

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Abstract

This study presents an experimental investigation of metastable region take place for refrigerant flow through adiabatic and non-adiabatic capillary tube of window type air conditioner. Large numbers of experiments are carried out to explain the effect of length of straight and helical capillary tube on metastable region under adiabatic and non-adiabatic conditions. for the case of adiabatic capillary tube, three different length are selected (70,100 and 150) cm and two helical capillary tube, the length of each tube is 100 cm with two coil diameters (2 and 6) cm. For the non-adiabatic capillary tube, the straight capillary tube suction line is 150 cm while the length of non-adiabatic helical capillary tube is 200 cm with 8 cm coil diameter. The results show that the length is the most influence parameters on beginning of metastable region. In addition the helical coil tube effect on the beginning of metastable region. As well as for the adiabatic and non-adiabatic capillary tube it is concluded that mass flow rate is the main parameters on beginning of metastable region. Also effect of length and coiling on both pressure drop and mass flow rate are discussed. The CFD commercial code, ANSYS CFX 16.1 based on finite volume method using K- turbulence model considering the homogeneous flow between phases applied to straight capillary tube. The present numerical data has been validated with the present work experimental data and with other researchers. A good agreement is obtained which can be lead to use ANSYS CFX 16.1 in the design and optimization of capillary tube in air-conditioner.


Article
INVESTIGATION OF COMBINATION BETWEEN LATENT AND SENSIBLE HEAT STORAGE MATERIALS ON THE PERFORMANCE OF FLAT PLATE SOLAR AIR HEATER
دراسة التاثير المشترك لمادة الخزن الحراري الكامن والمحسوس كمادة خزن حراري جديدة على اداء سخان الهواء الشمسي المستوي

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Abstract

In this work, a combination between latent heat storage materials (LHSm) and sensible heat storage materials (SHSm) as new storage heat material in flat plate solar air heater was tested experimentally. PCM (paraffin wax) at a certain ratios (10%) and (20%) were used as LHSm with a pure cement (base material) as SHSm. The experimental tests was done indoor at irradiance of (1000W/m2) with forced convection, the mass flow rate of air are (0.5kg/min) and (1.13kg/min). The results indicated that the enhancing thermo-physical properties of adding pure cement by a certain ratios of paraffin wax led to enhancement in thermal energy stored. The percentage increasing in storage heat duration time was (29%) for compound cement with (10%PCM), (38.4%) for compound cement with (20%PCM), compared with pure cement at (0.5kg/min) air mass flow rate. And at (1.13kg/min) air mass flow rate, it was (33.3%) for compound cement with (10%PCM) and (52.6%) for compound cement with (20%PCM) compared with pure cement.


Article
FABRICATION OF ADVANCED MORTAR FOR BUILDING APPLICATION
تصنيع مونه إسمنتية متقدمة لتطبيقات البناء

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Abstract

In this research, cement mortar specimens were prepared with sand to cement (1:2.75) and (1, 2, and 3 wt%) of ceramic oxides (MgO, ZnO and Al2O3) at different particle sizes (11.8, 38.8, 109.8 nm), respectively. At curing time (7days), the (structural, thermal and physical) characteristics of the mortar specimens were investigated. The dry density and porosity results show that the values of density increased by (23.4, 15.6, and 9.5%), and the values of porosity decreased by (76.2, 63.8, and 56.2%) for (MgO, ZnO, and Al2O3), respectively with respect to the reference mortar specimen. The thermal conductivity results show that the values of thermal conductivity decreased by (47.27, 40.66, and 51.16%) for (MgO, ZnO and Al2O3) respectively, with respect to the reference mortar specimen . Results of characterizations tests (XRD and optical microscope) showed that the reference mortar specimen has high roughness with large number of Ca(OH)2 crystals, as well as the presence of pores, while after adding the nanopowders, it showed a decrease or disappearance of Ca(OH)2 and produced homogeneous structure of calcium silicate hydrate compound (C-S-H), in addition to a large decrease in the pores and surface roughness. This explains the significant improvement in the properties of cement mortar mixed with nanopowders, hence these mortars were very appropriate for covering walls, buildings and other outdoor building applications.


Article
ENHANCEMENT THE HEAT TRANSFER FOR TWO-PHASE FLOW THROUGH A RECTANGULAR RIBBED VERTICAL CHANNEL
تحسين انتقال الحرارة لجريان ثنائي الطور خلال قناة مستطيلة عمودية مضلعة

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The heat transfer coefficient and temperature distribution of two phase flow (water, air) in rectangular ribbed vertical channel was investigated experimentally and numerically in this work for different values of water and air superficial velocities (0.0421, 0.0842, 0.1158, 0.1474 and 0.1684 m/s) and (1.0964, 1.425, 1.644, 1.864 and 2.193 m/s), respectively, at constant heat flux (120 W). The distribution of temperature along the channel was photographed using thermal camera and compared with images for the corresponding contours which found numerically. The experimental results of heat transfer coefficient compared with computational fluid dynamics model simulated by Ansys fluent 15.0. A good agreement has been found between the experimental and numerical data, where the percentage deviation between the experimental and the numerical results is (1% - 6% ). The results showed that, the local heat transfer coefficient increased by adding ribs, it also increased as the velocity of the flow increased.


Article
DEVELOPMENT OF FUZZY LOGIC MODEL FOR CUTTING PARAMETERS INFLUENCE ON THE CUTTING FORCE AND THE CHIP THICKNESS RATIO DURING TURNING OF ALUMINUM ALLOY 1350-O
تطوير نموذج المنطق الضبابي لنمذجة تأثير متغيرات القطع على قوة القطع ونسبة سمك النحاتة أثناء خراطة سبيكة الألومنيوم 1350-O

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Abstract

In turning operation, numerous parameters are utilized to analyze machinability. Parameters, for instant, tool wear, tool life, cutting temperature, machining force components, power consumption, surface roughness, and chip thickness ratio are frequently utilized. The goal of this work is to model the effect of cutting parameters (cutting speed, depth of cut and feed rate) on the machining force and chip thickness ratio during turning ductile aluminum 1350-O. Four fuzzy logic models were built to model the relationship between cutting parameters and the three force components of machining force and the chip thickness ration. The inputs to all fuzzy logic models are cutting speed, depth of cut and feed rate. Whereas, the output for first, second, third and fourth models are cutting force, passive force, feed force and chip thickness ratio, respectively. All fuzzy models showed good match to the experimental data and the computed correlation coefficients were larger than or equal 0.9998. Those models were used to optimize the cutting process and give the optimum cutting parameters.


Article
INFLUENCE THE QUENCHING AND TEMPERING ON THE MICROSTRUCTURE, MECHANICAL PROPERTIES AND SURFACE ROUGHNESS, OF MEDIUM CARBON STEEL
تاثيرالاخماد والمراجعة على البنية المجهرية , الخواص الميكانيكية , خشونة السطح للحديد متوسط الكاربون

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One of ways to improve properties of materials without changing the product shape to obtain the desired engineering applications is heating and cooling under effect of controlled sequence of heat treatment. The main aim of this study was to investigate the effect of heating and cooling on the surface roughness, microstructure and some selected properties such as the hardness and impact strength of Medium Carbon Steel which treated at different types of heat treatment processes. Heat treatment achieved in this work was respectively, heating, quenching and tempering. The specimens were heated to 850°C and left for 45 minutes inside the furnace as a holding time at that temperature, then quenching process was performed in four types of quenching media (still air, cold water (2°C), oil and polymer solution), respectively. Thereafter, the samples were tempered at 200°C, 400°C, and 600°C with one hour as a soaking time for each temperature, then were all cooled by still air. When the heat treatment process was completed, the surface roughness, hardness, impact strength and microstructure tests were performed. The results showed a change and clear improvement of surface roughness, mechanical properties and microstructure after quenching was achieved, as well as the change that took place due to the increasing toughness and ductility by reducing of brittleness of samples.


Article
STUDY OF SOME PROPERTIES FOR COLD-CURING ACRYLIC RESIN REIENFORCED WITH NANO YTTRIUM OXIDE
دراسة بعض الخصائص لراتنج الاكريليك البارد المعزز بنانو أوكسيد اليتريوم

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Abstract

Through the last two to three dictate, composite materials had being applied enormously in many industry fields. This is as fact that this type of materials possess; high strength to weight ratio, high stiffness, and limit thermal conductivity. In this work Nano-Yttrium oxide with (0%, 1%, 2%, 3% and 4%) weight fraction had been added, as reinforcement phase, to acrylic resin (cold curing). Various physical and mechanical tests had done for determining the development in the properties of the prepared composite samples like: hardness, tensile strength, thermal conductivity, water absorption and density. The results show: decreasing tensile strength with increasing Nano-Y2O3 weight fraction, maximum decline in tensile strength was at (4) % Y2O3, about (16.2) % of Acrylic strength; increasing in hardness with increasing Nano-Y2O3 weight fraction, maximum hardness was at (4) % Y2O3, about (107) % of Acrylic hardness, no obviously density change with increasing Nano-Y2O3 weight fraction, decreasing water adsorption with increasing Nano-Y2O3 weight fraction, maximum decreasing in water absorption percentage was at (4) % of Y2O3, about (93) % of Acrylic water absorption, decreasing thermal conductivity with increasing weight fractions of Nano-Y2O3, maximum decline in thermal conductivity was at (4)% of Y2O3 , about (90)% of Acrylic thermal conductivity


Article
IMPROVED SOME PROPERTIES OF HIGH DENSITY POLYETHYLENE SYNTHESIS USING FIBER GLASS FOR PIPES AND RESERVOIRS APPLICATIONS
تحسين بعض خصائص البولي أثيلين عالي الكثافة باستخدام الألياف الزجاجية لتطبيقات الأنابيب والخزانات

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In this paper, the effect of surface modification of short glass fiber on some properties of high-density polyethylene composite was investigated. The chemical treatment of short glass fiber (SGF) with solvent ethanol was achieved, and composites with weight fraction (0.5, 2.5, 4wt. %) were fabricated. Mechanical behavior tests include (tensile strength, impact, and hardness tests) and structure test (FTIR) were used. Values of mechanical tests for treated short glass fiber – reinforced High density polyethylene composites were much better than the neat high density polyethylene. The tensile strength value of composite from (37 to 41 MPa), impact strength from (83 J/m² to 100 J/m²), and hardness from (64 to 86 N/m²). Result of FTIR test showed physical reaction without the formation of new peaks.


Article
CORROSION – BUCKLING INTERACTION OF 6061-T4 AL ALLOY FIXED – PINNED COLUMNS – EXPERIMENTAL STUDY
الانبعاج المقترن بالتاكل للالمنيوم(ِAl6061-T4 ) للاعمدة المثبتة – المتمفصلة . دراسة عملية

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Compression buckling experimental tests was carried out for long and intermediate columns made of 6061-T4 AL- alloy. Two different soil corrosion time were adopted i.e.30 days and 60 days using 27 samples. The experimental analysis revealed that increasing the corrosion time negatively affects the mechanical properties of metals such as the specimens of 60 days corroded have 1.68% reduction in ultimate strength, also increasing the corrosion time reduces the critical load such as the maximum reduction was 4.24% in critical buckling load for 60 days corrosion time. Perry-Robertson theory was applied to the experimental data and it was found that the above theory can satisfactory predicted the critical buckling load (Pcr) with a factor of safety equal to 1.2. The ratio of corroded Pcr to dry Pcr was always less than unity. This indication explains the effect of pitting corrosion on buckling behavior of 6061-T4 AL- alloy.


Article
CUMULATIVE FATIGUE DAMAGE OF 7075 ALUMINUM ALLOY REINFORCED WITH ALUMINA AL2O3
تلف الكلال التراكمي لسبيكة الالمونيوم 7075المقوى بالالومينا AL2O3

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The reinforcement of Aluminum alloys opens a wide range of industrial application for these alloys in areas where reduction of weight has first priority, in General this operation known as metal matrix composite (MMC). In this study the nanocomposite material were fabricated using stirring time for 6 minutes at 450 rpm stirring speed .Al-7075 alloy was the base metal and the reinforcement nanocomposite material was the Alumina Al2O3 of 10 nanometer in grain size , which is used as weight percentage (wt%) for 0.3,0.5,0.7 wt% Al2O3. The results show that the best enhancement in fatigue life and strength were occurred at 0.3 wt% of Al2O3.


Article
HOT CORROSION OF CERIA-YTTRIA STABILIZED ZIRCONIA PLASMA SPRAYED THERMAL BARRIER COATING BY EUTECTIC VANDIUMPENTAOXIDE-SODIUM SULFATE
التاكل الساخن لطبقات الرش بالبلازما للحواجز الحرارية للسيريا-ياتريا المثبتة للزركونيا بالاويتكتيك لخماسي اوكسيد-الفناديوم- كبريتات الصوديوم

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The high temperature corrosion behavior of thermal barrier coating (TBC) system consisting of IN-738 LC superalloy substrate, air plasma sprayed Ni24.5Cr6Al0.4Y (wt%) bond coat and air plasma sprayed ZrO2-20 wt% ceria-3.6 wt% yttria (CYSZ) ceramic coat were characterized. The upper surfaces of CYSZ covered with 30 mg/cm2 , mixed 45 wt% Na2SO4-55 wt% V2O5 salt were exposed at different temperatures from 800 to 1000 oC and interaction times from 1 up to 8 h. The upper surface plan view of the coatings were identified for topography, roughness, chemical composition, phases and reaction products using scanning electron microscopy, energy dispersive spectroscopy, talysurf, and X-ray diffraction. XRD analyses of the plasma sprayed coatings after hot corrosion confirmed the phase transformation of nontransformable tetragonal (t') into monoclinic phase, presence of YVO4 and CeVO4 products. Analysis of the hot corrosion CYSZ coating confirmed the formation of high volume fraction of YVO4, with low volume fractions of CeOV4 and CeO2. The formation of these compounds were combined with formation of monoclinic phase (m) from transformation of nontransformable tetragonal phase (t').

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