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1 - Evaluation of the cryogenic effect on friction stir processed AA7075/Si matrix nanocomposites
Navid Molla Ramezani Behnam Davoodiشماره 1 , دوره 13 , زمستان 2024Friction-stir processing is a green manufacturing process of surface composite fabrication and surface modification. To achieve this critical goal, the type of cooling and lubrication is of great importance. Therefore, in this paper, the cryogenic effects were investiga چکیده کاملFriction-stir processing is a green manufacturing process of surface composite fabrication and surface modification. To achieve this critical goal, the type of cooling and lubrication is of great importance. Therefore, in this paper, the cryogenic effects were investigated on FSP tool wear and surface quality of aluminum matrix nanocomposite. The silicon carbide (SiC) nanopowder was used as a reinforcing phase. The effects of cooling strategy and tool rotation speed on the tool wear, microhardness, surface roughness, and energy dispersive spectroscopy analysis (EDS) were studied due to the investigation of the effect of the parameters. The cooling procedure was in dry condition and cryogenic conditions. Also, the rotation speed was set in three levels, and other parameters were considered constant. The FSP tools were examined under a scanning electron microscope. Also, the wear mechanisms were investigated at different conditions. Results showed tool wear, surface roughness, and microhardness were improved in cryogenic conditions than in air conditions. Furthermore, with the presence of liquid nitrogen, metal matrix composite does not have any microstructure defects, such as micro-cracks. Also, energy dispersive spectroscopy analysis showed that SiC has suitable penetration in base material due to the existence of liquid nitrogen than dry conditions. پرونده مقاله
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1 - Evaluation of the cryogenic effect on friction stir processed AA7075/Si matrix nanocomposites
Navid Molla Ramezani Behnam Davoodiشماره 1 , دوره 13 , زمستان 2024Friction-stir processing is a green manufacturing process of surface composite fabrication and surface modification. To achieve this critical goal, the type of cooling and lubrication is of great importance. Therefore, in this paper, the cryogenic effects were investiga چکیده کاملFriction-stir processing is a green manufacturing process of surface composite fabrication and surface modification. To achieve this critical goal, the type of cooling and lubrication is of great importance. Therefore, in this paper, the cryogenic effects were investigated on FSP tool wear and surface quality of aluminum matrix nanocomposite. The silicon carbide (SiC) nanopowder was used as a reinforcing phase. The effects of cooling strategy and tool rotation speed on the tool wear, microhardness, surface roughness, and energy dispersive spectroscopy analysis (EDS) were studied due to the investigation of the effect of the parameters. The cooling procedure was in dry condition and cryogenic conditions. Also, the rotation speed was set in three levels, and other parameters were considered constant. The FSP tools were examined under a scanning electron microscope. Also, the wear mechanisms were investigated at different conditions. Results showed tool wear, surface roughness, and microhardness were improved in cryogenic conditions than in air conditions. Furthermore, with the presence of liquid nitrogen, metal matrix composite does not have any microstructure defects, such as micro-cracks. Also, energy dispersive spectroscopy analysis showed that SiC has suitable penetration in base material due to the existence of liquid nitrogen than dry conditions. پرونده مقاله -
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2 - Investigation of Mass Magnetic Abrasive Finishing Process on Compressor Blades
Seyed Alireza Rasouli Davood Noriشماره 4 , دوره 12 , پاییز 2023Attempts at research across various industries to achieve high-quality surfaces have led to the development of new finishing processes. Magnetic Abrasive Finishing is a novel technique where a magnetic field is employed to control an abrasive tool. Gas turbine compresso چکیده کاملAttempts at research across various industries to achieve high-quality surfaces have led to the development of new finishing processes. Magnetic Abrasive Finishing is a novel technique where a magnetic field is employed to control an abrasive tool. Gas turbine compressor blades are among the industrial components requiring high surface quality due to their exposed surfaces. The reduction in surface roughness on these components has a significant impact on the efficiency of motor turbines. This paper focuses on studying the Magnetic Abrasive Finishing process parameters for the free surfaces of Titanium blades. Using a mass Magnetic Abrasive Finishing machine, the influence of powder weight, type of abrasive particles, and gap on the variation of surface roughness is investigated through statistical methods such as the response surface. The fabrication of the machine and determination of magnet polarity are carried out using Maxwell simulation software. The Factorial method is employed for experiment configuration. Mechanically alloyed powders produced by ball mills are used in this study. Results demonstrate that employing the magnetic abrasive method can reduce the surface roughness of the blade by up to 33%. The empirical model derived from regression analysis is utilized to predict the variation in surface roughness. Variance analysis of the experimental results indicates the significance of all studied parameters. Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM) are employed for a qualitative evaluation of the results. پرونده مقاله -
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3 - Experimental investigation of one-pass and two-pass friction stir welding process of aluminum alloy 6061 with and without copper foil
Qadarat Mohammad Jassim Al-Issawii Maziar Mahdipour Jalilian Mahdi Karami Khorramabadiشماره 4 , دوره 12 , پاییز 2023In this research, two methods of conventional Friction Stir Welding (FSW) and two-pass friction stir welding have been used to weld AA6061-T6 alloy parts with a copper interlayer (copper foil. Based on the results, it was determined that the number of welding passes, th چکیده کاملIn this research, two methods of conventional Friction Stir Welding (FSW) and two-pass friction stir welding have been used to weld AA6061-T6 alloy parts with a copper interlayer (copper foil. Based on the results, it was determined that the number of welding passes, the presence or absence of copper foil as an interlayer, the number of welding passes, the direction of tool rotation and the direction of tool movement in the second pass strongly affect the strength and ductility of FSW. According to the results, the highest tensile strength and ductility belong to TP-D(Two-Pass, type D), TP-B(Two-Pass, type B), TP-C(Two-Pass, type C), TP-A(Two-Pass, type A), CF-Cu and CF(Conventional FSW) samples, respectively. The mentioned samples have growth of 21, 29, 45, 36 and 58% respectively compared to the CF sample. The highest strength growth was related to the TP-D sample, which experienced a 58% increase in tensile strength compared to the CF sample. The tensile strength efficiency of this sample is 89.3% compared to the base metal. The highest increase in ductility was related to the TP-D sample, which experienced a 35% increase in ductility compared to the CF sample. The ductility efficiency of this sample is 81.1% compared to the base metal. پرونده مقاله -
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4 - بررسی تولید مواد با استحکام بالا در فرآیند ECAP به کمک شبیه سازی سه بعدی
عرفان عباسی سید راوش احدیشماره 4 , دوره 1 , پاییز 1389در روش تغییرشکل در کانال‌های مساوی زاویه‌دار (ECAP)، ماده از داخل یک قالب با دو کانال متقاطع عبور کرده و تغییرشکل برشی شدیدی در ماده ایجاد می‌شود که به موجب آن کرنش‌های شدیدی در ماده پدیدار گشته و سبب ریزدانگی ساختار ماده می‌شود. در این تحقیق به چکیده کاملدر روش تغییرشکل در کانال‌های مساوی زاویه‌دار (ECAP)، ماده از داخل یک قالب با دو کانال متقاطع عبور کرده و تغییرشکل برشی شدیدی در ماده ایجاد می‌شود که به موجب آن کرنش‌های شدیدی در ماده پدیدار گشته و سبب ریزدانگی ساختار ماده می‌شود. در این تحقیق به کمک شبیه‌سازی سه‌بعدی فرآیند ECAP با استفاده از نرم‌افزار المان محدود اثر پارامترهای موثر نظیر سرعت پرس، زاویه‌ی کانال، زاویه‌ی گوشه‌ی قالب و ضریب اصطکاک بررسی شده و سپس تغییرات ساختار با نتایج آزمایشات تجربی مورد مقایسه و ارزیابی قرار گرفت. براساس نتایج حاصله انطباق مناسبی بین روش‌های ارزیابی صورت گرفته وجود دارد و شبیه‌سازی انجام شده می‌تواند جهت پیش‌بینی نتایج فرآیند به‌کار گرفته شود. پرونده مقاله -
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5 - تولید کامپوزیت پایه فلزی Tio2/Al5083 به وسیله روش فراوری اصطکاکی اغتشاشی (FSP)
رضا عبدی بهنق رسول سالک رستم محمد کاظم بشارتی گیویشماره 2 , دوره 1 , بهار 1389جوش حالت جامد به روش جوشکاری اصطکاکی اغتشاشی فرآیند جدیدی می‌باشد که دارای بازده بالا و بدون ضرر برای محیط زیست می‌باشد. جوش حالت جامد (FSW) به عنوان اختراعی مهم در جوش فلزات در یک دهه اخیر در نظر گرفته شده است. اخیرا فرآیند فرآوری اصطکاکی اغتشاشی (FSP) برای ب چکیده کاملجوش حالت جامد به روش جوشکاری اصطکاکی اغتشاشی فرآیند جدیدی می‌باشد که دارای بازده بالا و بدون ضرر برای محیط زیست می‌باشد. جوش حالت جامد (FSW) به عنوان اختراعی مهم در جوش فلزات در یک دهه اخیر در نظر گرفته شده است. اخیرا فرآیند فرآوری اصطکاکی اغتشاشی (FSP) برای بهسازی زیرساختاری مواد فلزی ابداع شده است که بر اصول روش جوشکاری اصطکاکی اغتشاشی بنا گشته با این تفاوت که در این فرایند جوشکاری در میان نیست و ابزار غیر مصرفی به درون قطعه رفته و دو ماده را مخلوط کرده و با تولید کامپوزیت پایه فلزی (MMC) خواص بهینه‌ای نسبت به فلز پایه حاصل می‌گردد. در این مقاله از ورق‌های Al5083 استفاده شده و کامپوزیت Tio2/Al5083 را به وسیله ریختن پودر فلزی Tio2 به درون ورق‌ها و استفاده از ابزارهای مختلف برای ایجاد کامپوزیت و مخلوط کردن پودر استفاده کرده‌ایم و بعد خواص مکانیکی کامپوزیت به وجود آمده را بررسی و با فلز پایه مقایسه کردیم. نتایج حاصل حاکی از آن است که خواص بسیار مطلوبی به دست آمده و سخت سازی سطح و ریز دانه کردن آلومینیوم مذکور که مد نظر بوده کاملا به دست آمده است. پرونده مقاله -
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6 - Enhanced Microstructure and Mechanical Properties of A216 Steel by Friction Stir Processing
Gholamreza Khalaj Gholamreza Ghaffari Bahram Abdolmalekiشماره 4 , دوره 11 , پاییز 2022One of the main problems in oil and gas pipelines is abrasion corrosion on the edges of the flow channel in the plug and ball valves. Under normal conditions, the gas is moving at a pressure of about 145 bar and an approximate speed of 70 feet per second; the suspended چکیده کاملOne of the main problems in oil and gas pipelines is abrasion corrosion on the edges of the flow channel in the plug and ball valves. Under normal conditions, the gas is moving at a pressure of about 145 bar and an approximate speed of 70 feet per second; the suspended particles in the gas collide with the edges of the flow channel and cause severe erosion on them. The abrasion resistance of steels depends mainly on their surface properties and can be increased by increasing the surface hardness by friction stir processing (FSP). In this study, A216-WCB steel, which is used in the manufacturing of casting parts for valves, flanges, and fittings, was processed using an FSP for one and three passes. The microstructure, hardness, and wear properties of the processed area were investigated. The results showed that two distinct zones, the stir zone (SZ) and the thermo-mechanical affected zone (TMAZ), are formed in the processed zone. Due to the FSP, the grain size in the stirring region decreased from 25 microns to about 3 microns. The hardness of the SZ increased from 165 Vickers to about 784 HV. Tensile strength increased by 24%, and elongation was reduced by 25% for the processed sample compared to the raw metal. This may be due to phase transformation to martensite and grain size refinement. Also, the abrasion resistance of the stirring area increased up to 2.5 times. پرونده مقاله -
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7 - Investigating the Effect of Titanium Addition on the Microstructure and Mechanical Properties of Ni-Hard 4 Cast Iron
Masoud Bahrami Alamdarlo Kamran Amini Vahid Nemati Najafabadi Mahyar Mohammadnezhadشماره 1 , دوره 5 , زمستان 2016Ni-Hard4 white cast iron is excellent wear resistant material and has been widely used in wearaffected equipment operated under extreme conditions, such as in mineral processing, cement, copper and iron manufacturing. In this study the effect of titanium addition (1.2, چکیده کاملNi-Hard4 white cast iron is excellent wear resistant material and has been widely used in wearaffected equipment operated under extreme conditions, such as in mineral processing, cement, copper and iron manufacturing. In this study the effect of titanium addition (1.2, 0.7 and 0.2 wt.%) to the Ni-hard 4 cast iron with the nominal composition of Si= 1.5%, Mn=0.5%, C=3%, P=0.05%, S= 0.05%, Mo= 0.1%, Cr= 8% and Ni= 5.5% was investigated. This study was focused on the hardness, tensile strength, wear resistance and microstructural changes of the Ni-hard 4 cast iron. The results were compared with the Ni-hard 4 titanium free cast iron and demonstrated that the carbide morphology changes from rough plane to the flower leaf due to titanium addition. In addition, results showed that by increasing the percentage of titanium, hardness, strength and wear resistance is improved. In the samples with 1.3% titanium, the hardness, strength and wear resistance improved for 35, 22.5 and 85% respectively as compared with the titanium-free samples. This behavior is a consequence of the chromium carbide replacement with the hard titanium carbides as well as grain refining. Investigating the worn out surface of the samples showed that the predominant wear mechanism is the combination of the adhesive and tibo-chemical. پرونده مقاله -
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8 - An Electrochemical Investigation on the Effect of Heat-Stable Salts on the Corrosion Resistance of Carbon Steel in MDEA Solution
Hojatollah Abnavi Esmaeil Jafariشماره 3 , دوره 10 , تابستان 2021The purpose of this study is to identify the influence of different concentrations of heat-stable salts (oxalate, acetate, formate, succinate, glycolate) on the carbon steel corrosion in MDEA solution. Natural gas usually contains acidic gases like CO2 and H2S along wit چکیده کاملThe purpose of this study is to identify the influence of different concentrations of heat-stable salts (oxalate, acetate, formate, succinate, glycolate) on the carbon steel corrosion in MDEA solution. Natural gas usually contains acidic gases like CO2 and H2S along with other sulphur components. These acidic gases have to be scrubbed off from the gas for environmental, operational, and economic reasons. A long-term experiment was conducted to investigate the corrosion behavior of carbon steel in HSS+MDEA solutions and surface analysis techniques (SEM, EDS) were carried out to characterize the morphologies and compositions of the surface layers. To obtain the corrosion behavior of carbon steel in different concentrations of HSS+MDEA solutions the potentiodynamic polarization tests were used. The result showed that the acetate had less corrosion effect and the oxalate had the greatest impact on corrosion of the carbon steel. According to the electrochemical results, these five heat stable salts didn’t have a significant corrosion effect on carbon steel till 5000 ppm concentration. پرونده مقاله -
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9 - The Effect of Power and Maximum Cutting Speed on the Material Removal Rate and Cutting Volume Efficiency in CO2 Laser Cutting of Polycarbonate Sheets
Majid Hashemzadeh Mehdi Mahammadiشماره 1 , دوره 9 , زمستان 2020In the laser cutting process some well-known parameters, e.g. laser power and cutting speed, play major roles in the performance of the process. Each parameter or a combination of parameters can affect the material removal volume and cutting volume efficiency. The purpo چکیده کاملIn the laser cutting process some well-known parameters, e.g. laser power and cutting speed, play major roles in the performance of the process. Each parameter or a combination of parameters can affect the material removal volume and cutting volume efficiency. The purpose of this research is to study the effect of power and maximum cutting speed on the material removal rate (MRR) and cutting volume efficiency (αVol) in CO2 laser cutting of polycarbonate (PC) sheets. A CO2 laser cutting machine with a maximum power of 130 W was used to cut PC sheets with thicknesses of 2 to 8 mm. The spot size of the focused beam was 0.1 mm on the upper surface of the sheet. The cutting experiments were carried out by varying the laser power from 20 to 100 W and the maximum cutting speed was found for each power. In the range of applied laser parameters for cutting of PC sheets, the results show that the MRR increases with power. The results also indicate that the MRR increases with maximum cutting speed and thickness. The cutting volume efficiency (αVol) increases with power until it reaches the apex of efficiency then, it slightly reduces with increasing power. پرونده مقاله -
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10 - بررسی اثر پارامترهای فرایند قالبگیری تزریقی ABS و PP به کمک آب با استفاده از روش بهینه سازی تابع هدف با معیارهای چندگانه (OEC)
طاهر ازدست زهرا محمدیان امیر حسین بهروش احمدضیاء احمدزیشماره 3 , دوره 1 , تابستان 1389در این تحقیق از بهینه‌سازی تابع هدف طراحی آزمایشی تاگوچی برای یافتن شرایط بهینه فرایند قالبگیری تزریق به‌کمک آب برای دو پلیمر ABS و PP استفاده شده است. به منظور قالبگیری تزریقی نمونه‌ها، قالب لوله‌ای دو سر با حفره مواد اضافه و نازل تزریق آب طراحی و ساخته شد. با تو چکیده کاملدر این تحقیق از بهینه‌سازی تابع هدف طراحی آزمایشی تاگوچی برای یافتن شرایط بهینه فرایند قالبگیری تزریق به‌کمک آب برای دو پلیمر ABS و PP استفاده شده است. به منظور قالبگیری تزریقی نمونه‌ها، قالب لوله‌ای دو سر با حفره مواد اضافه و نازل تزریق آب طراحی و ساخته شد. با توجه به اینکه توابع هدف مختلفی در این فرایند مدنظر است، لذا از روش بهینه‌سازی تابع هدف با معیارهای چندگانه کلی (OEC)استفاده شد. نوع مشخصه کیفی بزرگتر- بهتر برای تابع هدف OEC مورد استفاده قرار گرفت. توابع هدف خروجی در این تحقیق برای قطعات تولید شده میزان نفوذ آب در داخل قطعه و اختلاف بیشترین و کمترین انقباض در طول قطعه انتخاب شدند. سه متغیر زمان نگهداری، دمای قالب و زمان تأخیر به عنوان متغیرهای کنترل در نظر گرفته شدند. آرایه ارتوگونال استاندارد M9 تاگوچی برای طراحی استفاده گردید و از آنالیز واریانس(ANOVA) نتایج برای تجزیه و تحلیل آماری نتایج استفاده شد. . نتایج OEC نشان داد که در بین متغیرها، برای پلیمر ABS پارامتر زمان تأخیر بیشترین تأثیر را روی مشخصه کیفی محصول تولیدی داشته است و پس از آن دمای قالب و زمان نگهداری به ترتیب بر روی فرایند قالبگیری تزریقی به‌کمک آب مؤثر بوده‌اند ودر پلیمر PP فاکتور زمان نگهداری مؤثرترین فاکتور بر روی مشخصه کیفی محصول تولیدی بوده و پس از آن به‌ترتیب زمان تأخیر و دمای قالب بر مشخصه کیفی تاثیر داشته‌اند. پرونده مقاله
