Mathematical Modelling of Magnetic Abrasive Machining Hybrid Operation: A Review

الانهاء بالحث الممغنط هو طريقة انهاء سطحي غير تقليدي لإنتاج اجزاء ذات نوعية عالية والتي يسيطر عليها بالطاقة المغناطيسية. طورت عملية الحك الممغنط بعض الخواص الميكانيكية للسطح. بعض طرق الانهاء السطحي التقليدية مثل تنعيم السطح الداخلي، التجليخ والتنعيم الخارجي بدلت الان بهذه الطريقة. في هذا البحث (مراجعة) سنتناول بالتفصيل اساس عملية الانهاء بالحث الممغنط، متغيرات العملية وتأثيرها على المخرجات (الاستجابة)، نمذجة العملية وتطورها للسطوح المستقيمة. اضافة الى ذلك هناك نوع جديد من الانهاء بالحث الممغنط المندمج مع التشغيل الكهروكيمياوي لإنتاج التشغيل بالحك الممغنط الكهروكيمياوي. اداء النموذج الرياضي والامثلية المتعددة لتنبأ المخرجات مثل معدل الازالة المعدنية، الانهاء السطحي والمنطقة المتأثرة بالحرارة.... الخ وجدت للمقارنة بدلالة دقة وسرع التنبؤ.   Magnetic Abrasive Finishing (MAF) or super finishing is a modern unconventional finishing technique to produce high quality of parts, which is controlled by a magnetic energy. Magnetic abrasive operation develops some of the mechanical properties such as the surface quality. Nowadays, many of the traditional finishing technique such as honing, polishing and grinding are now being replaced by this process. In this review, principles of the MAF process, processing factors and their influence on the responses, the process modeling and development of the MAF method for flat surfaces will be examined in details research work in the literature. Additionally, there is a new type of MAF connected with Electrochemical Machining (ECM) to produce Electrochemical Magnetic Abrasive Machining (EMAM). The performance of models and multi-optimizing for predicting the responses such as metal removal rate (MRR), surface finish (SF), heat affected zone (HAZ) etc. are found to comparable in terms of the prediction accuracy and speed. &nbsp

Optimization of EDM Process Factors for Machining Al-Si Alloy Using Response Surface Methodology

        يقدم هذا البحث نهجا متكاملا لنمذجة العملية والأمثلية متعددة الاهداف لمتغيرات التشغيل بالشرارة الكهربائية لسبيكة الالمنيوم سيليكون (Al-Si) اعتمادا على نمط استجابة السطح (RSM) إلى جانب تكنيك دالة الرغبة (DF). أختيرت ثلاث متغيرات منفصلة كمدخلات وهي تيار النبضة (Ip)، فترة إفراغ النبضة (Ton) وفترة توقف النبضة (Toff) للتأكد من تأثير المتغيرات الثلاث سابقة الذكر على المخرجات المتمثلة بمعدل إزالة المادة (MRR)، معدل بلى القطب (EWR) وخشونة السطح (Ra). تحليل عام للتفاوت (ANOVA) عند درجة من الأهمية مقدارها 5% لتعيين المعاملات الأكثر تأثيرا، وأنجز اختبار مدى كفاءة كافة النماذج. ولفهم السلوك الشامل لقابلية تشغيل لسبيكة الالمنيوم سيليكون (Al-Si) تحت أوضاع التشغيل المتفاوتة، تم إجراء تحليل التأثير الأساسي. بينت النتائج ان معدل الازالة المعدنية يزداد مع رفع تيار النبضة وفترة إفراغ النبضة. يمكن الاستحصال ايضا على نقصان في كل من معدل بلى القطب وخشونة السطح عن طريق خفض تيار النبضة ووقت إفراغ النبضة. ومع ذلك، فإن تيار النبضة هو العامل المتحكم (الاكثر تأثيرا) على معدل الازالة المعدنية وخشونة السطح متبوعا زمن تفريغ النبضة وزمن توقف النبضة، في حين أن في معدل بلى القطب فان تيار النبضة هو العامل الاكثر تأثيرا يليه زمن توقف النبضة وزمن إفراغ النبضة. أخيرا استعملت أسلوب الامثلية متعددة الاهداف بالاعتماد على نظرية دالة الرغبة للاستحصال على المقدار الامثل لمتغيرات التشغيل بحيث يمكن الاستحصال من خلالها على اعلى مقدار لمعدل الازالة المعدنية وأدنى مقدار لكل من متوسط بلى القطب وخشونة السطح مع المتغيرات المؤثرة.This work exhibits an incorporated way to deal with the procedure demonstrating and multi-target improvement of EDM parameters of Al-Si based on response surface methodology (RSM) combined with desirability function (DF) method. The’ effect’ of’ process’ parameters   for’ example, pulse current (Ip), pulse’ on’ time’ (Ton) as well as pulse’ off’ time’ (Toff) on’ metal removal’ rate’ (MRR), electrode’ wear’ rate’ (EWR) and’ surface’ roughness’ (Ra), were analyzed. An extensive investigation of difference (ANOVA) at fixed indicative level of 5%, was done to completely distinguish the most persuasive parameters, and the sufficiency of all fitted relapse models were checked. To completely comprehend the trademark machinability conduct under various EDM conditions, fundamental effect investigation. The results indicate that MRR increases with the rising Ip and Ton. Low EWR and Ra can be acquired by diminishing Ip and Ton. Be that as it may, the Ip is the most commanding parameter pursued by Ton and Toff for MRR and Ra whereas in the EWR, the Ip is the foremost factor, followed by the Toff and Ton. Lastly, a multi-optimization way dependent upon the desirability function (DF) idea was used to discover ideal blends of machining parameters so that it was capable to produce the the most extreme estimation of MRR and least estimations of EWR and Ra, inside the noteworthy information parameters

Optimization of Friction Stir Welding Parameters of Al 6061 and Al 7075 Using GRA

لحام الخلط الاحتكاكي هو تكنولوجيا واعدة لربط سبائك الألومنيوم غير المتشابهة. سبائك الالمنيوم تستخدم بصورة شائعة في صناعات الفضاء مثل ابدان الطائرات والالواح والأجنحة نظرا لمتانته العالية نسبه الى وزنه. لذلك هنالك محاوله للوصول الى أمثليه متغيرات عمليه اللحام الاحتكاكي عند لحام سبيكتين من الالمنيوم هما6061 و7075 باستخدام برنامجMinitab 16  من اجل تحسين خصائص الشد مثل اجهاد الخضوع (YS) ومتانة الشد القصوى(UTS) ونسبة الاستطالة(E) . طريقه Taguchi استخدمت كأساس لتحليل العلاقة الرمادية (GRA) باستخدام عاملين هما سرعه دوران الاداة (TRS) وسرعه اللحام (WS بأربع مستويات. النتائج اظهرت ان المتغيرات التي هي سرعه دوران الاداة وسرعه اللحام لها تأثير كبير على اجهاد الخضوع ومتانة الشد القصوى ونسبة الاستطالة. كما اظهرت النتائج ان طريقه Taguchi المستخدمة كأساس لتحليل العلاقة الرمادية تحسن المخرجات لسبيكتي الالمنيوم 6061 7075 الملحومتان.Friction stir welding (FSW) is proved as a promising welding technology for joining dissimilar aluminium alloys. Aluminium alloys are used extensively within the aerospace industry for applications such as fuselage and wing skin panels due to their high strength to weight ratio. Therefore, an effort is made to optimize the process parameters of FSW using Al 6061 and Al 7075 alloys by the Minitab 16 program in order to enhance  tensile properties such as elongation (E), yield stress (YS), and ultimate tensile strength (UTS). Grey relational analysis (GRA) based on the Taguchi method is applied using two factors tool rotational speeds (TRS) and welding speed (WS) with four levels. Results show that the variables, namely the tool rotation speed and welding speed have a significant effect on yield stress, ultimate tensile strength and elongation. Results also show that the Taguchi based grey relational approach improved properties of output response of welded Al 6061 and Al 7075 aluminum alloys

Optimization of Cutting Condition for Turning Operation Based On the Taguchi Method

البحث الحالي هو محاولة لنمذجة ظروف القطع في عملية الخراطة باستخدام طريقة تاكوشي وتصميم التجارب. المخرجات (الاستجابة) كانت فقط خشونة السطح. استخدم الفولاذ المقاوم للصدأ AISI 316 SS كمادة مشغلة واختيرت سرعة القطع، معدل التغذية، عمق القطع ونصف قطر رأس العدة كظروف للقطع. استخدمت المصفوفة العمودية القياسية L18 لتصميم التجارب. حللت النتائج التي تم الحصول عليها باسخدام البرنامج Minitab16. نفذ تحليل التباين ANOVA لايجاد العوامل المؤثرة على خشونة السطح. حسبت القيم المستحصلة كاستجابة باستخدام صيغ رياضية وتم تاكيدها بواسطة اختبار التاكيد. من النتائج العملية نلاحظ ان معدل التغذية له التاثير الاكبر على قيم الخشونة متبوعا بسرعة القطع ونصف قطر رأس العدة وعمق القطع.Present dissertation work has attempted to optimize the various significant cutting conditions for turning process by Taguchi method and design of experiments. The response variable is surface roughness (Ra). The stainless steel AISI 316 SS has been used as a workpiece material. The various cutting conditions selected for the study were cutting speed, feed rate, depth of cut and nose radius. A standard L18 orthogonal array was selected for design of experiments. The results obtained from the experimental runs were analyzed using Minitab16 software. Analysis of Variance (ANOVA) for Signal-to-noise (S/N) ratio was done to find the most contributing cutting conditions affecting the Ra. The corresponding values of the response parameter were also calculated using mathematical formulae and confirmed by performing validation experimentation. From the present experimental study, it is observed that Ra in turning process is mainly affected by all input parameters. Feed rate was the most significant factor affecting the Ra followed by cutting speed, nose radius and depth of cut

Wire Arc Additive Manufacturing of Steel: Deposition Patterns Effect on Microstructure and Mechanical Properties

Recently, Metal Inert Gas (MIG) -based weld deposition process is one of the deposition-based Additive Manufacturing (AM) processes. This technique has created considerable interest due to the advantages it offers of being able to produce fully functional, complex, dense metallic objects. The study mainly aims to investigate the influence of a variety of deposition patterns on the microstructure and the mechanical properties of steel materials built on a low alloy steel substrate by MIG process. Experiments were carried out using a semi-automated MIG welding to built the samples manufactured using five different deposition patterns (longitudinal, transverse, right network, oblique and oblique network). Microscopy generally showed coarse equiaxed grains in the lower regions, fine equiaxed grains in the middle regions and columnar grains in the upper regions. The maximum hardness was (201HV) for the sample built with the oblique pattern, while the minimum hardness was (170 HV) for the sample built longitudinally. The highest average tensile strength value was (480 MPa) for the sample built longitudinally. The fracture mode was significantly ductile.The lowest average tensile strength value was however (262.5 MPa) for the sample built transversely, and the fracture mode was brittle

Modeling and analysis of process parameters in EDM of Ni35Ti35Zr15Cu10Sn5 high-temperature high entropy shape memory alloy by RSM Approach

The Electrical Discharge Machining (EDM) technique demonstrates proficiency in fabricating precise and intricate geometries, especially in challenging-to-machine materials like high-entropy shape memory alloys. Analyzing and optimizing machining parameters are crucial for their direct impact on mechanical properties and overall product efficiency. The main responses chosen to evaluate the processes are material removal rate (MRR), electrode wear rate (EWR), and surface roughness (Ra). At the same time, the associated machining conditions were discharge current (Ip), pulse-on time (Ton), and pulse-off time (Toff). EDM is a multi-response process; therefore, the method of Response Surface Methodology (RSM) is utilized to assess the influence of machining parameters on Ni35Ti35Zr15Cu10Sn5 (at%) high-temperature high entropy shape memory alloy (HT-HE-SMA) using a copper electrode. Based on a center composite design (CCD), experiments were analyzed using Minitab19 software. To identify the most influential parameters, a thorough analysis of variance (ANOVA) at various significance levels (5%) was performed, checking the sufficiency of all fitted second-order regression models. Discharge current, pulse-on time, and pulse-off time were identified as significant factors that affect output (MRR, EWR, and Ra). The model adequacy of the current experimental investigation is perfect, with determination coefficients (R2) of 97.82% for MRR, 95.36% for EWR, and 99.53% for Ra

Wire Arc Additive Manufacturing of Steel: Deposition Patterns Effect on Microstructure and Mechanical Properties

Recently, Metal Inert Gas (MIG) -based weld deposition process is one of the deposition-based Additive Manufacturing (AM) processes. This technique has created considerable interest due to the advantages it offers of being able to produce fully functional, complex, dense metallic objects. The study mainly aims to investigate the influence of a variety of deposition patterns on the microstructure and the mechanical properties of steel materials built on a low alloy steel substrate by MIG process. Experiments were carried out using a semi-automated MIG welding to built the samples manufactured using five different deposition patterns (longitudinal, transverse, right network, oblique and oblique network). Microscopy generally showed coarse equiaxed grains in the lower regions, fine equiaxed grains in the middle regions and columnar grains in the upper regions. The maximum hardness was (201HV) for the sample built with the oblique pattern, while the minimum hardness was (170 HV) for the sample built longitudinally. The highest average tensile strength value was (480 MPa) for the sample built longitudinally. The fracture mode was significantly ductile.The lowest average tensile strength value was however (262.5 MPa) for the sample built transversely, and the fracture mode was brittle

Phenotypic variability and disparities in treatment and outcomes of childhood arthritis throughout the world: an observational cohort study

Background To our knowledge, the characteristics and burden of childhood arthritis have never been studied on a worldwide basis. We aimed to investigate, with a cross-sectional study, the prevalence of disease categories, treatment methods, and disease status in patients from across different geographical areas and from countries with diverse wealth status

Phenotypic variability and disparities in treatment and outcomes of childhood arthritis throughout the world: an observational cohort study.

BACKGROUND:To our knowledge, the characteristics and burden of childhood arthritis have never been studied on a worldwide basis. We aimed to investigate, with a cross-sectional study, the prevalence of disease categories, treatment methods, and disease status in patients from across different geographical areas and from countries with diverse wealth status. METHODS: In this multinational, cross-sectional, observational cohort study, we asked international paediatric rheumatologists from specialised centres to enrol children with a diagnosis of juvenile idiopathic arthritis, according to International League of Associations for Rheumatology criteria, who were seen consecutively for a period of 6 months. Each patient underwent retrospective and cross-sectional assessments, including measures of disease activity and damage and questionnaires on the wellbeing and quality of life of the children. We qualitatively compared the collected data across eight geographical areas, and we explored an association between disease activity and damage and a country\u27s gross domestic product (GDP) with a multiple logistic regression analysis. FINDINGS: Between April 4, 2011, and Nov 21, 2016, 9081 patients were enrolled at 130 centres in 49 countries, grouped into eight geographical areas. Systemic arthritis (125 [33·0%] of 379 patients) and enthesitis-related arthritis (113 [29·8%] of 379) were more common in southeast Asia, whereas oligoarthritis was more prevalent in southern Europe (1360 [56·7%] of 2400) and rheumatoid factor-negative polyarthritis was more frequent in North America (165 [31·5%] of 523) than in the other areas. Prevalence of uveitis was highest in northern Europe (161 [19·1%] of 845 patients) and southern Europe (450 [18·8%] of 2400) and lowest in Latin America (54 [6·4%] of 849), Africa and Middle East (71 [5·9%] of 1209), and southeast Asia (19 [5·0%] of 379). Median age at disease onset was lower in southern Europe (3·5 years, IQR 1·9-7·3) than in other regions. Biological, disease-modifying antirheumatic drugs were prescribed more frequently in northern Europe and North America than in other geographical settings. Patients living in countries with lower GDP had greater disease activity and damage than those living in wealthier countries. Damage was associated with referral delay. INTERPRETATION: Our study documents a variability in prevalence of disease phenotypes and disparities in therapeutic choices and outcomes across geographical areas and wealth status of countries. The greater disease burden in lower-resource settings highlights the need for public health efforts aimed at improving equity in access to effective treatments and care for juvenile idiopathic arthritis