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Article
Effect of Shot Peening on Mechanical Properties for Steel AISI 1008

Authors: Mohammed Abdulraoof Abdulrazzaq محمد عبد الرؤوف عبد الرزاق --- Zeyad D. Kadhim --- Wassan S. Hussain
Journal: DIYALA JOURNAL OF ENGINEERING SCIENCES مجلة ديالى للعلوم الهندسية ISSN: 19998716/26166909 Year: 2019 Volume: 12 Issue: 2 Pages: 54-64
Publisher: Diyala University جامعة ديالى

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Abstract

Residual stress has a significant effect for improving engineering properties for metals .Most of the surface treatments produce compressive residual stress at the metal surfaces, which reduce crack initiation and increasing the metal resistance to fatigue, which is shot peening process. Shot peening is usually used for this purpose for producing plastic deformations of surface of the metal which can lead to creation high residual compressive stresses at metal surface .This research include study the influence of shot peening process on fatigue resistance, surface hardness and surface roughness for low carbon steel (AISI 1008). This process accomplished with different times which were (10, 20 and 30(minutes. The result of the fatigue test showed that the fatigue limit increase when shot peening time increased and the best fatigue limit obtained when shot peening process was carried out at 30 minutes. Results of hardness test showed that surface hardness increased with increase of shot peening time. It can be seen that highest value of surface hardness is obtained from shot peening process at time (30 minutes) which is (235.1 HVN). Results of surface roughness test showed that the surface roughness of metal increased when time of shot peening increased


Article
Effect of Alumina (Al2O3) Particles on The Mechanical Properties of Magnesium (Mg)
تأثير جزيئات الألومينا (Al2O3) على الخواص الميكانيكية للمغنيسيوم (Mg)

Authors: Hayder Muneam Abed Zaid حيدر منعم عبد زيد --- Abdul Rahman N. Abed عبد الرحمن نجم عبد --- Hala Salman Hasan هالة سلمان حسن
Journal: AL-NAHRAIN JOURNAL FOR ENGINEERING SCIENCES مجلة النهرين للعلوم الهندسية ISSN: 25219154 / eISSN 25219162 Year: 2019 Volume: 22 Issue: 2 Pages: 124-130
Publisher: Al-Nahrain University جامعة النهرين

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Abstract

In the present study, magnesium-based composites reinforced with different volume fractions (3, 5, 10, and 15) vol.% of micro sized Al2O3 particulates were fabricated by powder metallurgy technique which involves mixed, compacted and sintered. Powders were mixed by ball milling (without balls) for 6 hours at rotation speed 60 rpm. Then powder was compacted at 550 MPa and sintered at 530˚C for 2 hours. Microstructures of sintered composites have been investigated by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX) and X-ray diffraction (XRD) energy dispersive. SEM image of sinter samples exhibit good bonding between the magnesium matrix and the alumina. The microhardness and wear resistance of micro composites has been improved significantly compared to that of pure magnesium. Highest value of microhardness is 97 HV at the volume fraction of 10 vol.% Al2O3.

في هذه الدراسة ، تم تصنيع مركبات أساسها المغنيسيوم معززة بكسور حجمية مختلفة (3، 5، 10، 15 %) كنسبة حجمية. من جسيمات الألومينا المايكروية الحجم والتي تم تصنيعها بواسطة ميتالورجيا المساحيق والتي تتضمن الخلط ، الضغط والتلبيد. تم خلط المساحيق عن طريق خلاط الأسطوانة (بدون كرات) لمدة 6 ساعات بسرعة دوران 60 دورة في الدقيقة. تم ضغط العينات عند 550 MPa وتم تلبيدها عند 530 م˚ لمدة 2 ساعة. تم فحص المجهرية عن طريق مسح المجهري الإلكتروني (SEM) ، تحليل العناصر المركبة للمركب باستخدام التحليل الطيفي للأشعة السينية المشتتة (EDS) و أجري تحليل حيود الأشعة .(XRD) تشير النتائج التجريبية لنتائج صورة SEM لمركبات العينات الملبدة إلى وجود ارتباط جيد بين ارضية المغنيسيوم والألومينا. تم تحسين صلادة و مقاومة البلى للمركبات بشكل ملحوظ عند مقارنةً بالمغنيسيوم النقي. أفضل القيم لتحسين 97 HV في الكسر الحجمي 10٪من.Al2O3 أظهر اختبار الضغط أن مقدار للمقاومة الانضغاطية القصوى (UCS) أفضل قيم للتحسين بنسبة حجمية 5% من Al2O3 هي حوالي 179MPa .


Article
Recycling waste papers in green cement mortars
اعادة تدوير النفايات الورقية لانتاج مونة سمنتية خضراء

Author: Aseel B. Al-Zubaidi اسيل باسم الزبيدي
Journal: Iraqi Journal of Physics المجلة العراقية للفيزياء ISSN: 20704003 Year: 2019 Volume: 17 Issue: 40 Pages: 135-144
Publisher: Baghdad University جامعة بغداد

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Abstract

This work investigates the utilization of waste papers (natural and industrial) i.e (citrus aurantium and papers A4) mortars containing specified contents 0.5%, 1%, 1.5% of waste papers were prepared and cured. Mechanical characteristics such as compressive and bending strengths, hardness and water absorption were determined for the mortars mixed with the waste papers and compared with those obtained from the pure mortars. Results showed that the addition of waste paper leads to increase the hardness to (69 - 68.5) shore D for (natural and industrial) wastes materials respectively comparing with pure specimen 66 shore D. The compressed strength of the mortar cement specimen cured for 28 days from 13 MPa to (17-18) MPa for (natural and industrial) wastes materials, respectively.

يهدف البحث الى الاستفادة من النفايات الورقية (الطبيعية والصناعية) أي (أوراق الحمضيات كالنارنج والأوراق الصناعية (A4 واعادة تدويرها في إعداد مونة السمنت باضافات محددة 0.5%, 1%, 1.5% من أوراق النفايات. وقد تم تحديد الخصائص الميكانيكية مثل قوة الانضغاط وقوة الانحناء والصلابة وامتصاص الماء لمونة السمنت الخضراء الممزوجة مع أوراق النفايات ومقارنة مع المونة السمنتية النقية بدون اضافات و أوضحت النتائج أن إضافة النفايات الورقية يؤدي إلى زيادة الصلابة إلى (69-68.5) شور D لمواد النفايات (الطبيعية والصناعية) على التوالي مقارنة مع العينة النقية 66 شورD. ان قوة الانضغاط لعينة الأسمنت المغمورة بالماء لمدة 28 يوم ازدادت من 13 ميكا باسكال إلى (17-18) ميكا باسكال لمواد النفايات الورقية (الطبيعية والصناعية) على التوالي.


Article
Improving the Mechanical Properties of Fiber Metal Laminate Composite Used in Aircraft Wing
تحسين الخصائص الميكانيكية للمادة المتراكبة المتعددة الطبقات المستخدمة في جناح الطائرة

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Abstract

The purpose of this study is to reduce weight and improve the mechanical properties of aircraft wing using Hybrid materials known as fiber metal laminates (FMLs). In this study, seven layers were used to produce the FMLs that consist of aluminum alloy2024-T3 reinforced by carbon and glass fibers bonded with blend of epoxy-resole. The Carbon Glass Reinforced Aluminum Laminates (CAGRALLs) was used as FMLs. The results showed that The CAGRALLs gave good mechanical properties because of increasing in tensile strength, elongation at fracture and impact toughness except flexural strength by comparing with other FMLs using commercial epoxy. The increasing in layers led to weaken adhesion force between layers of FMLs caused decreasing almost mechanical properties. The FMLs has good mechanical properties by using carbon and glass fibers by comparing with carbon and jute fibers. The CAGRALLs have higher numbers of cycles at failure under cyclic loadings than Aramid Reinforced Aluminum Laminates (ARALLs). The CAGRALLs have lower density by comparing with aluminum alloy 2024-T3 that used in manufacturing of aircraft wing.

الغرض من هذه الدراسة هو تقليل الوزن و تحسين الخصائص الميكانيكية لجناح الطائرة باستخدام مواد المتراكبة وهجينة (FMLs). في هذه الدراسة تم استخدام سبع طبقات لانتاج طبقات المادة المركبة التي تتالف من طبقات معدنية مدعمة بالالياف الكاربونية والالياف زجاج تلصق جميعها بخليط بالايبوكسي ريزول كمادة لاصقة. طبقات الالمنيوم مدعمة بالياف الزجاج و الكاربون (CAGRALLs) استخدمت كطبقات تدعيم للمادة المتراكبة. اذ اظهرت النتائج ان الخصائص الميكانيكية جيدة للمادة المتراكبة (CAGRALLs) وذالك بزيادة الاجهاد الشد,استطالة عند الكسر و متانة عند الصدمة ما عدا الاجهاء الانحناء مقارنة طبقات المادة المتراكبة اخرى (FMLs) باستخدام الايبوكسي التجاري كمادة لاصقة. الزيادة في عدد الطبقات تؤدي الى ضعف قوة التلاصق بين الطبقات مما يؤدي الى نقصان في اغلب الخصائص الميكانيكية. طبقات المادة المتراكبة اعطت خصائص ميكانيكية جيدة باستخدام الالياف الكاربون و زجاج مقارنة مع الالياف الكاربون و الالياف الجوت. طبقات المادة المتراكبة (CAGRALLs) تمتلك اعلى عدد دورات لنفس الاجهاد المطبق عند الفشل تحت الاحمال الترددية بالمقارنة مع طبقات الالمنيوم مدعمة بالالياف اراميد (ARALLs). طبقات الالمنيوم مدعمة زجاج كاربون تمتلك كثافة قليلة مقارنة مع سبيكة الالمنيوم (2024-T3) المستخدمة في صناعة جناح الطائرة.


Article
Study of the Effect of Al2o3&B4c Particles Reinforcement on Some Physical and Mechanical Properties for Aluminum Alloy 6063 by Powder Metallurgy Technique

Author: Salah Fadhil Abduljabbar
Journal: DIYALA JOURNAL OF ENGINEERING SCIENCES مجلة ديالى للعلوم الهندسية ISSN: 19998716/26166909 Year: 2019 Volume: 12 Issue: 3 Pages: 29-36
Publisher: Diyala University جامعة ديالى

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Abstract

Powder metallurgy technique utilized in samplespreparing. Samples were compacted by using colduniaxial pressing then followed by sintering process at600 oC under inert gas. Results showed improving in(Brinell Hardness, wear resistance & compressionstrength) and increasing in (density, porosity & waterabsorption). Brinell Hardness increasing (106. –114.7), compression strength increasing (35.1 – 40.8)N/mm2and decrease wear rate (6.6*exp(-8) –4.22*exp(-8)) g/cm at time 30 min. with (0 – 20)%Al2O3&B4C. While increase apparent density (2.76 –2.83) g/cm3, Bulk Density increase (2.71-2.82) g/cm3apparent porosity decrease (1.88 – 0.193) % and waterabsorption decrease (0.699 – 0.068) % at (0 – 20) %Al2O3&B4C


Article
Optimization Using Taguchi Method for Physical and Mechanical Properties of Bio Mimicking Polymeric Matrix Composite for Orthodontic Application

Author: Jenan S. Kashan
Journal: Engineering and Technology Journal مجلة الهندسة والتكنولوجيا ISSN: 16816900 24120758 Year: 2019 Volume: 37 Issue: 5part (A) Engineering Pages: 181-187
Publisher: University of Technology الجامعة التكنولوجية

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Abstract

This work take in consideration the application of Taguchi optimizationmethodology in optimizing the parameters for processing (composition,compounding pressure) and their effects on the output physical (Density and trueporosity) properties and mechanical(fracture strength and microhardness)properties for the Nano HA,Al2O3 fillers reinforced HDPE hybrid compositematerial for orthodontic application. An orthogonal array of the Taguchiapproach was used to analyses the effect of the processing parameters on thephysical and mechanical properties. On the other hand, the surface roughnessand particle size distribution were also calculated to study their effect on theoutput properties. The result shows that the Taguchi approach can determine thebest combination of processing parameters that can provide the optimal physicaland mechanical conditions, which are the optimum values (the optimumcomposition was15HA/ 5Al2O3/80HDPE, and optimum compounding pressurewas102 MPa.


Article
EFFECT OF OPERATION CONDITIONS ON MECHANICAL PROPERTIES OF AA7020-T53 ALLOY WELDED BY FRICTION STIR WELDING

Authors: Isam Tareq Abdullah --- Zaman Khalil Ibrahim
Journal: Journal of Engineering and Sustainable Development مجلة الهندسة والتنمية المستدامة ISSN: 25200917 Year: 2019 Volume: 23 Issue: 2 Pages: 42-55
Publisher: Al-Mustansyriah University الجامعة المستنصرية

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Abstract

Friction stir welding -FSW- is a new process of joining AA7020- T53 aluminum alloy sheet. There are few parameters which effects of FSW such as spindle speed, feed rate, tool design and tool tilt angle. In this search, the effect of tool rotational speed (spindle speed) and travel speed (feed rate) on mechanical properties are discussed. The FSW technique was performed using three different of rotational speeds and three different traverse speeds, while other parameters are kept constant to compare between joints. It was found that the best mechanical properties can be obtained from using high spindle speed and high feed rate. The ultimate tensile strength increases approximately 25% while the yield stress and elongation increases approximately 19% and 57% respectively, when used spindle speed (900r.p.m) and feed rate (50 mm/min).


Article
IMPROVING MECHANICAL PROPERTIES OF LIGHTWEIGHT FOAMED CONCRETE USING SILICA FUME AND FIBERS

Authors: Suhad Mohammed Abd --- Dhamyaa Ghalib Jassam
Journal: Journal of Engineering and Sustainable Development مجلة الهندسة والتنمية المستدامة ISSN: 25200917 Year: 2019 Volume: 23 Issue: 2 Pages: 184-199
Publisher: Al-Mustansyriah University الجامعة المستنصرية

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Abstract

Lightweight foamed concrete (LWFC) is characterized as a light in self-weight, self-compacting (no need vibration), self-leveling, and thermal and sound isolation. The application of (LWFC) in the building construction is limited because of its the low strength and the low ductility. In this study the workability of the fresh mix of (LWFC), the hardened properties include, compressive strength, tensile splitting strength, flexural strength, and modulus of elasticity were evaluated. This study focuses mainly on the effect of the adding of silica fume and fibers on the mechanical properties of (LWFC). Silica fume was added as 5% and 10% by the weight of cement. Steel fiber and polypropylene fiber volume fraction were of (0.2%, 0.4%), While the hybrid fibers (steel+ polypropylene) volume fraction was (0.2% steel+0.2%PP), and (0.4%steel+0.2%PP) of the total mix volume. The results of the program test show that the increase of silica fume improves the mechanical properties of (LWFC) significantly. The adding of fibers to the (LWFC) reduces the flowability and improves the mechanical properties. The hybrid fibers mix (0.4% steel+0.2% PP) presented the best test result of the mechanical properties as (10%,21%,53%, 24.4%) for the compressive strength, flexural strength, tensile splitting strength, and modulus of elasticity, respectively.


Article
Effect of Heat Treatment on Properties of Titanium Biomedical Alloy

Authors: Jassim M. Salman Al-Murshdy --- Bassim Jaber Ghayyib
Journal: Journal of University of Babylon مجلة جامعة بابل ISSN: 19920652 23128135 Year: 2019 Volume: 27 Issue: 1 Pages: 232-546
Publisher: Babylon University جامعة بابل

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Abstract

The aim of this work to study the effects of heat treatments on the alloy (Ti6Al4V) which produced by powder metallurgy methods and consists of a mixture of the following powders (titanium 90%, aluminum 6% and vanadium 4%).The heat treatments (sintering process) take place in different time of stay.The alloy (Ti6Al4V) used as biomaterials in the medical field due to their excellent properties such as : high corrosion resistance, high wear resistance, high breaking strength, higher ductility, non-toxic and non-magnetic, suitable elasticity coefficient, where used as an alternative to replacing damaged hard tissues such as orthopaedic, osteosynthesis, full hip joint, knee joint and dental implants.The elements were weighed by a highly sensitive electronic balance, the powder was mixed for five hours, Then press with a pressure (700 MPa) to transition to green cylindrical samples with a diameter of 13 mm.The sintering process was carried out at 1100 °C.The porosity of the samples decreases at high temperatures and time of stay to a certain extent and then increase porosity at very high temperatures due to the growth of particle and the expansion of gases.The density of the samples after the sintering process increases with increasing the temperature because increase the mass diffusion of particles and reduces porosities that increase contact points between particles.The sintering processes lead to increase the hardness, where the hardness was tested in the Vickers hardness method. The wear increased by increasing (load, time and sliding distance), and increase the hardness leads to a low volume loss (the amount of metal lost a few) as the relationship between them is inverse.To study the corrosion behavior of the samples that have been sintering processes under different time of stay and to perform this test (tafel Extrapolation test) in 0.9 NaCl solution, where the sample is subjected to high temperature and a long period of stay and therefore This lead to increases the diffusion and increases the contact points between the particles and increase the forces of bonds between the particles and this leads to increased corrosion current and therefore the oxidation process to be a high degree and this leads to the higher rate of corrosion.

الهدف من هذا العمل هو لدراسة تأثير المعاملات الحرارية علىالسبيكة Ti6Al4V)) التي انتجت بطريقة ميتالورجيا المساحيق وتتكون من خليط من المساحيق التالية : تيتانيوم ٪90 المنيوم ٪6 فناديوم ٪4 المعاملات الحرارية (التلبيد) تحدث في فترات مكوث مختلفة •السبيكةTi6Al4V)) تستخدم كمواد حياتية في المجال الطبي نتيجة الى خواصها الممتازة مثل مقاومة تأكل عالية ٬ مقاومة بلى عالية ٬ مقاومة عالية للكسر٬ مطيلية عالية ٬ غير سام وغير مغناطيسي ٬معامل مرونة مناسب حيث تستخدم كبديل لاستبدال الانسجة الصلبة التالفة مثل تقويم و تثبيت العظم ٬مفصل الورك ٬مفصل الركبة و زروعات الاسنان •العناصروزنت بواسطة ميزان الكتروني عالي الحساسية ٬المساحيق خلطت لخمس ساعات ثم ضغط المساحيق بأستخدام جهاز المكبس مع ضغط 700 ميكا باسكال للانتقال الى النماذج الاسطوانية الخضراء مع قطر للعينات 13 ملم . عملية التلبيد تجري بدرجة حرارة 1100 °م. المسامية للعينات تقل في درجات الحرارة العالية وزمن المكوث الطويل الى حد معين ثم تزداد المسامية في درجات الحرارة المرتفعة جدا بسبب النمو الحبيبي وتمدد الغازات. كثافة النماذج بعدعملية التلبيد تزداد مع زيادة درجة الحرارة بسبب زيادة انتشار الجسيمات و نقصان المسامية التي تزيد نقاط التماس بين الجسيمات.عملية التلبيد تؤدي الى زيادة الصلادة ٬حيث الصلادة اختبرت بطريقة فيكرز. البلى يزداد بواسطة زيادة (الحمل ٬الزمن ٬ مسافة الانزلاق).وزيادة الصلادة تؤدي الى انخفاض الحجم المفقود (كمية المعدن المفقود قليلة) حيث العلاقة بينهم علاقة عكسية. لدراسة سلوك التآكل للنماذج التي اجري لها عمليات تلبيد في فترات مكوث مختلفة ولاداء هذا الاختبار (اختبار تافل) في محلول 0٫9 كلوريد الصوديوم ٬ حيث النموذج تعرض الى درجة حرارة عالية وفترة مكوث طويلة وهذا يؤدي الى زيادة الانتشار وزيادة نقاط التماس بين الجسيمات وزيادة قوى الاواصر بين الجسيمات وهذا يؤدي الى زيادة تيار التاكل ولذلك عملية الاكسدة على درجة عالية وهذا يؤدي الى معدل التآكل.


Article
Mechanical and Structural Properties of a Lightweight Concrete with Different Types of Recycling Coarse Aggregate
الخصائص الميكانيكية والانشائية للخرسانة الخفيفة باستخدام أنواع مختلفة من الركام الخشن الخفيف

Authors: Muyasser M. Jomaa’h --- Baraa Thaar Kamil --- Omer S. Baghabra
Journal: Tikrit Journal of Engineering Sciences مجلة تكريت للعلوم الهندسية ISSN: 1813162X 23127589 Year: 2019 Volume: 26 Issue: 1 Pages: 33-40
Publisher: Tikrit University جامعة تكريت

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Abstract

In the light of the world's technological development in the construction field and the continuous need to apply high-efficiency building materials because old methods are no longer used after the advent of the solutions characterized by fast applications and maximum protection in addition to reducing costs and increasingthe sustainability of the establishment and its design age. The lightweights of various installations are an urgent need to decrease the dead loads. Therefore, this study is a local focus on replacing the normal coarse aggregate with lightweight coarse aggregate (claystone (bonza), rubber, thermostone and polystyrene) in various volumetric ratios of (25, 50 and 75) % in addition to a preparation of reference mix. For the purpose of identifying and studying the important specifications the new concrete which contributes to the selfload reduction of the concrete by reducing the total density of the mixture, models of cylinders and standard prisms were prepared, to evaluate the compressive strength and the splitting tensile strength respectively. In addition to that the modulus of rupture and the unit weight, where carried out. The tests results indicated a drop in the mechanical properties of the concrete with increase in the lightweight coarse aggregate, mechanical properties values: compressive strength, rupture modulus, splitting tensile strength and flexural strength were between (10.66-28.99) MPa (1.122-3.372) MPa, (3.606-6.83) MPa and (20.101-25.874)MPa compared with a reference mixes (38.44MPa), (3.969MPa), (10.476MPa) and (26.940)MPa respectively for mixes of (25, 50 and75)% with different light coarse aggregate , also the values of an oven-dry density were between (1665.5-2287.58)kg/m3 compared with reference mixes (2426.41kg/m³). The best concrete mix was (M7, M10) of low density (1598.4 kg/m3) and (1580.4) kg /m3 and the compression strength within the permissible limits (15.47) MPa.

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