Metallurgical Engineering

Abstract:  Iron hardening is a critical process in metallurgy, employed to improve the hardness, strength, and durability of iron and steel components. This paper explores the various methods used in iron hardening, including heat treatment techniques such as annealing, normalizing, quenching, and tempering, as well as surface hardening methods like case hardening, induction hardening, and flame hardening. It also discusses the role of work hardening, including cold working and strain hardening, in enhancing material properties. The paper provides a practical guide to the preparation of iron surfaces and selection of appropriate hardening methods for different applications, highlighting the importance of safety considerations and quality control. Additionally, it examines emerging trends in iron hardening technologies, including automation, energy-efficient techniques, and advancements in laser and plasma hardening. The future of iron hardening is poised for significant developments driven by the demand for more precise, sustainable, and cost-effective methods, especially in industries requiring high-performance materials.

Stiffeners are used in the construction of beams used in crane systems. The negative effect of thermal effect is increased by joining these reinforcements with welded manufacturing methods continuously along the beam. Due to the thermal deformation effect, distortion and related beam distortions occur. Within the scope of this study, SYSWELD Visual Assembly welded manufacturing simulation programme was used to eliminate the thermal deformation effects that occur in welded manufacturing processes before production. Finite element simulations and analyses were performed to minimise distortions and distortions caused by welding of reinforcements.
Increasing raw material, material, labour and energy costs in welded manufacturing processes in industrial applications day by day necessitate optimisation in operational welded jointing methods. In crane beams, the direction and magnitude of deformations and distortions that may occur within the distortion tolerances in welded manufacturing operations, and the negative effects of welded manufacturing stress concentration can be determined before production as a result of finite element analysis studies carried out through the SYSWELD Visual Assembly welded manufacturing simulation program. In this study, the necessity of using intermittent discontinuous welding method along the beam of the welding seams of the reinforcements in the constructions in the crane industry was determined as a result of the analyses carried out in this context. In addition, it has been concluded that in crane steel constructions; if TS EN 1993-1-8 standard is directly applied in welded manufacturing processes, constructions will be more economical; if the Regulation on Design, Calculation and Construction Principles of Steel Structures is used, a safer and safer crane system will be manufactured.

Practical use of superconducting wires that use liquid nitrogen refrigerant is presently under way. One potential candidate of such superconducting wires is Bibased oxide superconducting wire. The potential of this type of superconducting wire was demonstrated successfully when Sumitomo Electric’s Bi-based oxide superconducting wire was used in the transmission line to supply electricity to about 70,000 households in Albany, New York for nine months in 2007. Due to this success, practical applications of this Bi-based oxide superconducting wires are expected to expand in the future. However, for Bi-based oxide superconducting wires to become commonplace, higher critical current must be achieved in order to obtain improved power transmission capability and enable the downsizing of electromagnets and motors. To improve the critical current of wires, crystal orientation must be enhanced and hetero-phase must be reduced. Figure 1 shows the cross-section of the microstructure of Bi-based...

Bu çalışmada, genel yapı çeliği (Ç1020) ve paslanmaz çelik (AISI 316) malzemelerin yüzeyine sıcak daldırma yöntemiyle alüminyum (Al) kaplama uygulanmıştır. Yüzeyde oluşan Al kaplamanın mikroyapısı incelenerek, yüksek sıcaklık oksitlenmesine karşı gösterdiği direnç incelenmiştir. Numuneler 750 °C'deki sıvı Al içinde 10 dakika süreyle bekletilerek yüzeyleri Al ile kaplanmıştır. Daha sonra bu numunelere 800 °C sıcaklıkta 1 ve 6 saat süre ile nötr ortamda difüzyon tavlaması uygulanmıştır. Elementlerin difüzyonu, difüzyon tabakası kalınlığı ve oksitlenmeye karşı gösterdiği direnç incelenmiştir. Al kaplama yapılan ve yapılmayan numuneler 900 °C sıcaklıkta ve farklı sürelerde yüksek sıcaklık oksidasyonuna maruz bırakılarak yüzeyde oluşan ağırlık değişimleri ölçülmüştür. Al kaplanmış çelik numunelerde önemli miktarda ağırlık değişimi olmaması, Al kaplamanın çeliği oksitlenmeden koruduğunu göstermiştir. Malzemelerin bileşimindeki Fe, C, Al, Ni ve Cr elementlerinin Al kaplama ve difüzyon tabakasındaki değişimleri mikroprob analizi ile incelenmiştir. In this study, the surface of SAE 1020 and AISI 316 were applied to aluminium (Al) coating by hot deep method. The oxidation resistance and microstructures were investigated of Al coating applied to the surface of different steels. Sample surfaces were coated with Al at the temperature of 750 °C in 10 minutes durations. Experimental samples were subjected to at the 800 °C temperature and diffusion tempering with 1 and 6 hours durations. The changes in the thickness of diffusion layer and microstructure of the surface, as a result of the processes applied, were examined. Weight variations in the samples oxidized in atmospheric conditions under the temperature of 900 °C with varying durations have also been measured. It was found that steel material which changes of little weight of the samples coated with Al resisted more than without coated Al for oxidation. It was indicated that coated with Al surface of steel protected from oxidation The changes of elements Fe, C, Al, Ni and Cr were investigated by microprobe analyses in surface region.

Bu calismada, genel yapi celigi (C1020) ve paslanmaz celik (AISI 316) malzemelerin yuzeyine sicak daldirma yontemiyle aluminyum (Al) kaplama uygulanmistir. Yuzeyde olusan Al kaplamanin mikroyapisi incelenerek, yuksek sicaklik oksitlenmesine karsi gosterdigi direnc incelenmistir. Numuneler 750 °C’deki sivi Al icinde 10 dakika sureyle bekletilerek yuzeyleri Al ile kaplanmistir. Daha sonra bu numunelere 800 °C sicaklikta 1 ve 6 saat sure ile notr ortamda difuzyon tavlamasi uygulanmistir. Elementlerin difuzyonu, difuzyon tabakasi kalinligi ve oksitlenmeye karsi gosterdigi direnc incelenmistir. Al kaplama yapilan ve yapilmayan numuneler 900 °C sicaklikta ve farkli surelerde yuksek sicaklik oksidasyonuna maruz birakilarak yuzeyde olusan agirlik degisimleri olculmustur. Al kaplanmis celik numunelerde onemli miktarda agirlik degisimi olmamasi, Al kaplamanin celigi oksitlenmeden korudugunu gostermistir. Malzemelerin bilesimindeki Fe, C, Al, Ni ve Cr elementlerinin Al kaplama ve difuzyon taba...

Permanent Downhole Monitoring Systems have now become a standard component of well completion. The processing and interpretation of continuously recorded downhole pressure and temperature data provide static and dynamic reservoir characteristics, which can be used to develop and optimize production processes. This paper explores the applications of data from these systems for well testing, determining reservoir permeabilitythickness, wellbore skin, static reservoir pressure, identifying fractures and barriers, optimizing initial production, waterflooding, and enhanced oil recovery (EOR). Additionally, by developing models, this data can be used to estimate production rates and gas-oil ratio (GOR). Simulated models can be calibrated with continuous data, such as pressure, production rates, and GOR, resulting in higher accuracy compared to conventional methods that rely on estimated data. The use of downhole sensors not only directly reduces production costs but also enables optimal and sustainable reservoir production, thereby improving the recovery factor.

Maqolada to'qimachilik sanoati chiqindilarini an'anaviy va yangi qayta ishlash usullari tadqiq etilgan bo'lib, mazkur turdagi chiqindilardan foydalanish muammolari tahlil etilgan. Tayanch so'zlar: To'qimachilik chiqindilari, paxta tolasi chiqindisi, kalta tolali chiqindilar, zig'ir tolali chiqindilar, noto'qima mato, chiqindisiz texnologiya.

J. Hampl, B. Smetana, VŠB-TU Ostrava, Faculty of Metallurgy and Materials Engineering, Czech Republic J. Odehnal, PILSEN STEEL, s.r.o., Pilsen, Czech Republic The paper analyzes the technological parameters, micro-purity and mechanical properties of castings of steel alloyed with calcium. The effect of calcium on the steel was analyzed on samples taken in the process of casting heavy castings and ingots of the weight of ranging from 40 000 to 60 000 kg. Samples for the determination of the liquidus temperature and the solidus temperature of cast steels were analysed using differential thermal analysis (DTA). The production of low alloyed steel grades was performed on the EAF ASEA-SKF facilities and the production of highalloyed steels on the EAF ASEA-SKF SS-VOD facilities. The purity calcium was added into the steel by the injection of a stuffed profile.

In this study, statistical values of microhardness were investigated in terms of temperature and duration of aged aluminium 2XXX and 6XXX alloys. AA 2024 and AA 6063 aluminum alloys were solution treated at two different temperatres of 490°C and 520°C. Then all samples were cooled to room temperature. After this process, the samples were aged at three different temperatures (140°C, 180°C, 220°C) for ten different periods of time (2, 4, 6, 8, 10, 12, 14, 16, 18 and 20 h.). The microstructure of the aged samples was examined by optical SEM-EDS and X-Ray analysis. The hardness values of the aged samples were tested by microhardness tests. The samples were examined by Multivariate Analysis of Variance (MANOVA) with a confidence level of %95 to find out whether a statistically significant difference occurs. As a result of this analysis, temperature and duration on the wear behaviours of aged aluminium 2XXX and 6XXX alloys were statistically significant in microhardness values.

Super alloys are metallic materials for service at high temperature, so one of their most important properties is high temperature creep resistance. Other crucial material properties are fatigue life, phase stability, as well as oxidation and corrosion resistance. A conventional metal may be failed in high temperature machining condition and has poor creep resistance, so materials for working at high temperature and which having also good creep resistance are a critical issue in manufacturing. this paper present a review about the Nibase super alloys, which working at high temperature and also having a good machining property and having good creep resistance.

Изложены физико-химические закономерности специфической адсорбции органических соединений на металлах, сплавах и оксидах с учетом влияния потенциала электрода и природы растворителя. Показана возможность прогнозирования адсорбционных явлений в системе на основе электронных свойств органической молекулы и твердого тела (потенциал ионизации, работа выхода электрона, характеристические частоты в электронных спектрах). Описаны принципы выбора поверхностно-активных веществ в различных процессах (металлообработка, защита от коррозии, гальванотехника). Для научных и инженерно-технических работников, преподавателей, занимающихся проблемами создания новых технологий на основе адсорбционных явлений.

Penelitian ini membahas berbagai aspek teknis dalam industri manufaktur modern, khususnya terkait efisiensi sistem perpindahan panas, proses pemutihan serat, penggunaan pati dalam industri kertas, pencucian lumpur kapur, dan analisis penyebab sheet break dalam produksi kertas. Studi mengenai penukar panas menyoroti efektivitas desain heat exchanger tipe shell and tube, dengan fokus pada peningkatan kinerja dan mitigasi kontaminasi termal. Pada proses pemutihan serat, penelitian ini mengevaluasi dosis optimal NaOH dan durasi retensi yang menghasilkan peningkatan kecerahan serat sebesar 5%. Dalam industri kertas, perbandingan antara Native Starch dan wheat starch menunjukkan bahwa Native Starch memiliki kinerja lebih baik dalam meningkatkan kualitas kertas. Selain itu, analisis pencucian lumpur kapur mengungkap bahwa perbandingan air 1:5 dapat mengurangi kandungan alkali hingga 0,6% dan meningkatkan dryness hingga 64,53%, yang berpotensi menghemat biaya operasional industri. Sementara itu, penelitian terkait sheet break di PT. A menggunakan metode Statistical Process Control (SPC) dan Failure Mode and Effects Analysis (FMEA), mengidentifikasi paper tear dan holes paper sebagai penyebab utama. Hasil analisis menunjukkan perlunya perbaikan berkelanjutan untuk meningkatkan efisiensi produksi. Secara keseluruhan, penelitian ini memberikan wawasan komprehensif terhadap optimalisasi proses manufaktur untuk meningkatkan efisiensi dan kualitas produk.

Одним из важнейших этапов изучения нефтегазового потенциала месторождений, оценки качества и объёма запасов углеводородов, планирования дальнейших геологоразведочных работ является качественный отбор и анализ кернового материала с целью получения максимально возможной информации о структурно-текстурных особенностях породных образований.
Керн-это каменная летопись истории Земли. Поиск, разведка и дальнейшая разработка любого месторождения начинаются с изучения керна. Вопросы изучения и сохранения керна как важнейшего документа остаются актуальными и сегодня.
Целью настоящей работы является изучения керна c гидрохимическими исследованиями. Для изучения этого процесса в лаборатории были проведены гидрохимические исследования образцов, полученных путём смешивания керна с различными типами воды. Первоначально были изучены физико-химические свойства воды Каспийского моря и технической воды. Затем образцы керна измельчались и смешивались с различными типами воды (водой Каспийского моря, технической и дистиллированной). Лабораторные анализы проводились через раз-ные промежутки времени (3, 10 и 28 дней).

As a result of analyzing solutions and dry residues obtained during the study of the interaction of core samples with various types of water, it was found that the interaction of the core with distilled water resulted in the dissolution of Na++K+, Ca2+, Cl-, HCO3- ions and other components, leading to a decrease in the mass of the core dry residue by more than 2.0%. Interaction of the core with technical water led to an increase in mass by approximately 1.0%. In the case of seawater, the mass of the core dry residue decreased by more than 1.0%. The conducted research proves that the interaction of the core with different types of water causes certain physico-chemical processes, as a result of which the dissolution and precipitation of various salts occur. These results can have significant practical value in conducting analysis and determining the composition of various solutions.

The coking process is based on the transformation of coal into coke at high temperature. In non-recovery coke oven, heating is usually asymmetric, this may be due to the fact that heating is provided by controlled combustion of volatile matter of charged cake at oven crown and sole flue.In the present investigation, a simp lified temperature profiles were simu lated to typical temperature pro files of the non-recovery coke oven. The selection criterions of ovens were based on the oven temperature and coking time. Based on measurement of heating pattern, a numerical methodology was proposed for predicting temperature of the intermed iate point by using Lagrange interpolation method. Further, a MATLA B-based algorith m was used to predict the same heating pattern based on actual temperature profile in a non-recovery oven. The model was tested and validated with actual temperature profile of six industrial ovens. The model also reproduces the main feature of the measured temperature profile and shown good agreement with experimental data of industrial oven. The pred icted temperature pro file can discriminate d ifferent operating conditions and works well even at low level of temperature deviation. These variations will affect the heating rate and coking cycle, superimposed on the oven crown and sole temperature pattern. However, the operating temperatures were the most important factor fo r normal operation and found that the heating rate of normal operation was varied in the range of 1.06 -0.62℃/ min at a height of 200mm fro m top & bottom and centre of the charged cake.

Various degradation mechanisms are characterized in gas turbine rotor blades due to service conditions such as: high temperature and stress. Failure of turbine blade can have the tremendous effects on the safety and performance of the gas turbine engine. This paper investigates a first stage turbine blade failure in a 6.5 MW gas turbine. The blade is made of nickel-based superalloy, and the failure occurred in the airfoils after 6500 h of operation. Several examinations were carried out in order to identify potential failure reasons such as: visual examination, fractography and microstructural characterization used by optical and scanning electron microscopes (SEM) and energy dispersive X-ray (EDX). The precipitated phases morphology (carbides and γ′ (Ni3Al)) changed in the airfoil for example γ′ resolved and re-deposited in addition to decomposition of carbides. Furthermore, the fracture surface exhibits the local melting occurred and re-solidified in the leading edge. From analysis and experimental results of this study, overheating is shown to be the main reason of blade failure.

Ushbu maqolada temirni rudadan biogidrometallurgik usulda
ajratib olish texnologiyasi ko‘rib chiqilgan. Jarayon anaerob bakteriyalar yordamida
temirning noeruvchan Fe³⁺ shaklini eruvchan Fe²⁺ shaklga aylantirishga asoslangan.
Bakteriyalar organik moddalar metabolizmi natijasida karbonat angidrid hosil qilib,
eritmadagi temirning eruvchanligini oshiradi. Maqolada karbonat angidridni
eritmada ushlab turish orqali temirni yuqori samaradorlik bilan eritmaga o‘tkazish va
eritmani tozalash bosqichlari haqida ma’lumot berilgan. Elektroliz yordamida metall
temirni eritmadan ajratib olish usuli ham o‘rganilgan. Ushbu texnologiya an’anaviy
yuqori haroratli usullarga nisbatan ekologik xavfsizroq va energiyani tejaydi, ammo
jarayonning sekinligi va qo‘shimcha xarajatlar iqtisodiy samaradorlikka ta’sir
ko‘rsatadi. Bu maqola biogidrometallurgik usulni sanoat miqyosida qo‘llash
imkoniyatlarini ko‘rsatib, past sifatli rudalar va chiqindilarni qayta ishlashda yangi
imkoniyatlar yaratadi.

Historicamente, os cerâmicos são uns dos materiais mais antigos do mundo, em virtude do seu emprego desde a pré-história. São compostos inorgânicos formados por elementos metálicos e não metálicos, ligados através de ligações iônicas e/ou covalentes. As propriedades destes materiais são determinadas pelo tipo de ligação atômica, seu caráter amorfo ou cristalino, bem como pelos métodos de seu processamento. São caracterizados por apresentar propriedades tais como: resistência a altas temperaturas e a corrosão, dureza, são isolantes térmicos e elétricos.
Cerâmicas a base de argilas, como peças decorativas, louças de mesa e relacionadas com a construção civil (louças sanitárias, cimento, tijolos, revestimento de piso ou parede), são classificadas como cerâmicas tradicionais. São elaboradas a partir de materiais naturais (ou pouco beneficiadas), de pureza variável, e com pouca exigência de controle em seu processamento.
As cerâmicas avançadas ou cerâmicas de Engenharia são produzidas a partir de matérias primas sintéticas (óxidos, nitretos, carbetos e outros) ou beneficiadas industrialmente, com alto grau de pureza, e processamento controlado rigosamente. Estas cerâmicas são utilizadas em aplicações tecnológicas, estando presentes nas indústrias de componentes eletrônicos, de comunicação, automotiva, naval, aeroespacial, biomédica, e em muitas outras áreas industriais.
Tendo em vista a importância dos materiais cerâmicos ao promover um resultado significativo na sociedade, visto que estão presentes em diferentes aplicações indústrias, este livro apresenta diferentes pesquisas relacionadas a estudos originais e de revisões bibliográficas na abordagem dessa área da ciência e engenharia de materiais.

Полезная модель относится к сельскохозяйственной технике, в частности к оборудованию для сушки влажного растительного сырья с применением тепла при производстве кормов. Вихревая сушилка влажных кормов включает сушильную камеру с коническим дном и с патрубками для ввода газа-теплоносителя и для ввода сырья в ее нижней секции, патрубком для вывода использованного газа-теплоносителя и высушенного материала в верхней секции камеры, расположенный под сушильной камерой привод с приводным валом, проходящим через отверстие в днище камеры в ее нижнюю секцию, четыре измельчающих рабочих органа с возможностью вращения в горизонтальной плоскости и один измельчающе-перемешивающий рабочий орган с возможностью вращения, элементы которого размещены в плоскостях, параллельных коническому дну камеры, соединенные с приводным валом в нижней секции камеры, причем измельчающие рабочие органы имеют S-образную форму и лезвие вдоль боковой поверхности, измельчающе-перемешивающий рабочий орган имеет лезвие вдоль боковой поверхности, в верхней секции сушильной камеры имеется трубопровод в форме витка спирали, один конец которого соединен со средней секцией сушильной камеры, а другой - с патрубком для вывода использованного газа-теплоносителя и высушенного материала. Полезная модель позволит обеспечить повышение эффективности сушки влажных материалов, в частности кормов, предотвращение их комкования и возврат из верхней части сушильной камеры частиц высушенного материала в ее нижнюю часть.
The useful model relates to agricultural machinery, in particular to equipment for drying wet plant raw materials with the use of heat in feed production. Swirl dryer of wet feeds includes a drying chamber with a conical bottom and with spigots for input of gas-heat carrier and for input of raw materials in its lower section, a spigot for output of used gas-heat carrier and dried material in the upper section of the chamber, a drive located under the drying chamber with a drive shaft passing through an opening in the bottom of the chamber to its lower section, four chopping operating parts with the possibility of rotation in the horizontal plane and one chopping-stirring operating part with the possibility of rotation, elements of which are placed in planes parallel to the conical bed of the chamber, connected to the drive shaft in the lower section of the chamber, and the shredding operating parts have S-shape and a blade along the lateral surface, the shredding-stirring operating part has a blade along the lateral surface, in the upper section of the drying chamber there is a pipeline in the form of a spiral coil, one end of which is connected to the middle section of the drying chamber, and the other end of which is connected to the spigot for the outlet of the used heating gas and dried material. The useful model will allow to provide increase of efficiency of drying of wet materials, in particular feeds, prevention of their clumping and return of dried particles from the upper part of the drying chamber of the dried material particles to its lower part.

Toshkent davlat texnika universiteti ''Metallurgiya'' kafedrasi dotsenti Beknazarova Gulnoza Berdiyor qizi, Toshkent davlat texnika universiteti ''Metallurgiya'' kafedrasi katta o'qituvchisi Bektamishov Quvonchbek G'ayrat o'g'li, Toshkent davlat texnika universitetitalabasi Annotatsiya. Ushbu maqolada temirni rudadan biogidrometallurgik usulda ajratib olish texnologiyasi ko'rib chiqilgan. Jarayon anaerob bakteriyalar yordamida temirning noeruvchan Fe³⁺ shaklini eruvchan Fe²⁺ shaklga aylantirishga asoslangan.

Bu calismada referans numunenin kimyasal kompozisyonuna sirasiyla agirlikca %0.05 ve %0.075 oraninda niyobyum ve vanadyum ilave edilmesiyle uretilen yeni alasimlarin korozyon mekanizmasi %3.5 NaCl ortaminda arastirilmistir. Korozyon mekanizmasinin anlik belirlenmesine olanak saglayan Dinamik Elektrokimyasal Empedans Spektroskopisi (DEIS) yontemi ilk defa bu calismayla mikroalasim elementlerinin korozyona etkisinin belirlenmesinde kullanilmistir. Hazirlanan numunelerin yuzey morfolojisi 15 saat suren DEIS deneyleri sonunda optik mikroskopla incelenerek elektrokimyasal verilerle kiyaslanmistir. Deney sonuclarina gore niyobyum ve vanadyum miktarindaki artisin imal edilen yeni alasimlarin %3.5 NaCl ortaminda olusan korozyon hizini azalttigini gostermektedir. Deney sonunda elde edilen R ct degeri, alasim elementlerinin ilavesiyle ortalama %44 ila %57 oraninda artis gostermektedir. DEIS verileri ile optik resimler birbirini destekler niteliktedir. Alasim elementleri ilave edilmeyen numune...

Hydrated alu mina fro m three different sources like sodium alu minate liquor, waste alu miniu m dross and synthetic salt like alu miniu m sulfate were studied to obtain various form of alu miniu m hydro xide. Boeh mite (A l 2 O 3 .H 2 O), a form of hydrated alu mina, has better performance in obtaining alu mina, as the enthalpy of dehydration of boehmite is less as compared to gibbsite due to the less number of water mo lecules in the crystal lattice as compared to gibbsite. Precipitation of hydrated alumina was also studied by using synthetic alu miniu m sulfate solution with aqueous ammonia and alternating the sequence of reagent addition. Subsequently, the variation in the p H of precip itation and fo llo wed by variat ion of the ageing temperature produced a range of hydrated alu mina with different phases and crystallin ities. In another option hydrated alu mina was precipitated fro m the sulfuric acid leach liquor of waste aluminiu m dross by varying the pH of the precipitation followed by temperature o f ageing.

İnsanlık, belki de var olduğu ilk günden bu yana, hep bir şeyleri merak etmiş, incelemiş ve bulduklarıyla yetinmeyip araştırmaya devam etmiştir. Hiç bitmeyen bu merak ve araştırmalar sonucu bulduklarına yenilerini eklemiş ve teknoloji kavramının ortaya çıkmasını sağlamıştır. Ekonomideki gelişimlerin başlıca temel dayanağını teknolojik yeniliklerin sunmuş olduğu fırsatlar oluşturmaktadır. Malzeme teknolojisi açısından teknolojik gelişmelerin ilk basamağını malzeme özelliklerinin incelenmesi teşkil etmekte ve bu özellikler diğer bir tabir ile davranışlar malzemelerin içyapılarından etkilenmektedir. Malzeme içyapıları imalat esnasında uygulanan ısı ve deformasyondan etkilenerek değişim gösterebildiklerinden, imalat süreci sonunda malzeme özellikleri başlangıç malzemesinden ya da tasarımda dikkate alınandan farklı olabilmektedir. Bu çalışmada, çeliklerin sıcak yığma işlemi esnasında ve sonrasında mikro yapı değişimlerine ait literatürde bulunan ve kabul edilen malzeme modelleme kriterleri incelenmiştir. Ardından 1040 çeliği üzerinde yapılan çeşitli sıcaklıklardaki sıcak yığma deneyleri sonrasında numunelerin sertlikleri, mikro yapı görünümleri incelenmiş, sonuçlar modellemeler ile karşılaştırılmış ve irdelenmiştir. Öncelikle tüm yaşamım boyunca kararlarımın doğruluğuna inanıp bana olan desteklerini hiç esirgemeyen aileme; bilgi, deneyim ve sabrı ile bana rehberlik eden danışman hocam Sayın Doç. Dr. Şafak YILMAZ' a ve varlıkları ile hayatıma anlam katan arkadaşlarım Görkem KIZILTAN, Emrah DENİZ ve Nur PEHLİVANOĞLU' na teşekkürlerimi sunarım.

Electrowinning work is carried out on the roasted Eastern Desert complex carbonate ore residuum. Lead and its dioxide are electrodeposited from various electrolyte ore baths and the results showed a wide variety of ore electrolyte solutions, either in the form of soluble simple ore salts, or those containing complex ore anions. The optimum conditions and the efficiency of the electrolytic extraction are determined experimentally on the ore leach solutions.

The Vanadis ® 8 is a tool steel used in the manufacture of dies, punches and tools. It has a high carbon content combined with chromium, molybdenum and vanadium, and presents good performance in its mechanical properties. Usually, its chips obtained by machining are sold to companies that use remelting. However, this technique is considered expensive and harmful to the environment. Therefore, this work aimed to analyze the efficiency of the addition of vanadium carbide (VC) and molybdenum carbide (Mo 2 C) in the high energy ball milling of the Vanadis ® 8 steel. Microstructural analysis were performed in the pure steel and with 3% of VC and Mo 2 C additions. The milling parameters used were: speed of 350 rpm, ball-to-powder weight ratio of 15:1 and times of 4, 8 and 12 hours. The results indicated that the Vanadis ® 8 steel milled with VC presented the best microstructural results in all of the conducted tests.

ÖZET Soğuk hadde ile üretilmiş AA1100 alüminyum levhaların derin çekilmesinde karşılaşılan malzeme kökenli problemlerden kulaklanma üzerinde durularak, bu problemin ortadan kaldırılması veya minimuma indirilmesinde tav parametrelerinin etkisi incelenmiştir. Yapılan deneylerden elde edilen sonuçlar doğrultusunda tavlama sıcaklığı ve tavlama süresinin kulaklanma yüksekliğine en etken parametreler olduğu tespit edilmiştir. Son yıllarda yapay zeka yöntemleri sonuçların tahminlenmesinde yaygın olarak kullanılmaktadır. Bu çalışmada, kulaklanma yüksekliğinin tahminlenmesinde Gen İfadeli Programlama (GİP) kullanılmıştır. Giriş parametreleri olarak tavlama sıcaklığı ve tavlama süresi, çıkış parametresi olarak kulaklanma yüksekliği kabul edilmiştir. Bu parametreler yardımıyla GİP ortamında sadece dört işlem değişkenleri kullanılarak sonuçlar %95,89 oranında tahminlenmiştir.

ÖZET 1973 enerji krizinden sonra, alternatif enerji kaynakları üzerine çok yoğun bir şekilde araştırmalara başlanmıştır. Özellikle güneş enerjisi bu çalışmaların temelini oluşturmaktadır. Bir güneş enerjisi güç santrallerinde kullanılan sistemin başarısı özellikle malzemelerin doğru seçimine bağlıdır. Bu seçim genellikle verim, maliyet ve özel uygulamalara göre yapılmaktadır. Bu çalışmada yüksek sıcaklık güneş enerjisi sistemleri ve yüksek sıcaklık güneş malzemeleri tanıtılmıştır. Anahtar Kelimeler: Güneş enerjisi, yüksek sıcaklık, termal gerilme 1. GİRİŞ Güneş enerjisi, güneşten gelen ve dünya atmosferinin dışında şiddeti sabit ve 1370, yeryüzünde ise 0-1100 W/m 2 değerleri arasında olan yenilenebilir bir enerji kaynağıdır. Bu enerji ısıtmadan soğutmaya kadar çeşitli ısıl uygulamalarda ve elektrik üretiminde kontrollü olarak kullanılabilmektedir. Tablo 1. Türkiye'de bölgelere göre güneş enerjisi potansiyeli [1] Türkiye coğrafi konumu itibariyle güneş kuşağı içerisinde yer alan,...

It is emphasized that, earing problem which is one of the material origin problems that occurs during deep drawing of cold rolled AA1100 aluminium sheets and effects of the heat treating parameters to take away or minimize the earing problem were investigated. In recent years, artificial intelligence methods are widely used to estimate the results. In this study, Gene Expressive Programming (GEP) is used to estimate the height of earings. Annealing temperature and annealing time are approved as input parameters; earing height is approved as output parameter. Results are estimated with the ratio of 95,89 % at the GEP environment using only four arithmetical operation variables with the help of these parameters

Microstructure, phase composition and mechanical properties of a refractory high entropy superalloy, AlMo 0.5 NbTa 0.5 TiZr, are reported in this work. The alloy consists of a nano-scale mixture of two phases produced by the decomposition from a high temperature body-centered cubic (BCC) phase. The first phase is present in the form of cuboidal-shaped nano-precipitates aligned in rows along <100>-type directions, has a disordered BCC crystal structure with the lattice parameter a 1 = 326.9 ˘0.5 pm and is rich in Mo, Nb and Ta. The second phase is present in the form of channels between the cuboidal nano-precipitates, has an ordered B2 crystal structure with the lattice parameter a 2 = 330.4 ˘0.5 pm and is rich in Al, Ti and Zr. Both phases are coherent and have the same crystallographic orientation within the former grains. The formation of this modulated nano-phase structure is discussed in the framework of nucleation-and-growth and spinodal decomposition mechanisms. The yield strength of this refractory high entropy superalloy is superior to the yield strength of Ni-based superalloys in the temperature range of 20 ˝C to 1200 ˝C.

Open literature publications, in the period from 2010 to the end of January 2018, on refractory high entropy alloys (RHEAs) and refractory complex concentrated alloys (RCCAs) are reviewed. While RHEAs, by original definition, are alloys consisting of five or more principal elements with the concentration of each of these elements between 5 and 35 at.%, RCCAs can contain three or more principal elements and the element concentration can be greater than 35%. The 151 reported RHEAs/RCCAs are analyzed based on their composition, processing methods, microstructures, and phases. Mechanical properties, strengthening and deformation mechanisms, oxidation, and corrosion behavior, as well as tribology, of RHEA/RCCAs are summarized. Unique properties of some of these alloys make them promising candidates for high temperature applications beyond Ni-based superalloys and/or conventional refractory alloys. Methods of development and exploration, future directions of research and development, and potential applications of RHEAs are discussed.

In this paper we investigate flow phenomena related to tapping of silicon melt from a submerged arc furnace. The multiphase flow model predicts how the gas pressure variations inside the furnace crater zone may effect phenomena like the gas flow pattern inside different zones of the charge materials inside the furnace, the metal tapping flow rate, and the gas blow out from the furnace tap hole. The full 3D multiphase flow model of the furnace is based on the real geometry and the most probable physical properties of different zones in the furnace, such as density, charge material particles size, porosity and permeability of the packed beds on the furnace bottom. In addition different spatial arrangements of charge material zones have been investigated. The results of the model show that existence of the mentioned high pressure crater zone in the furnace has a considerable effect on the metal tapping and the gas flow rate from the tap hole. The predicted tapping rate compares well to...

The Norwegian ferroalloy industry has high ambitions regarding environmental standards. Basic research work has been performed to improve the fundamental understanding of ferroalloy processes and the environ- mental aspects. This paper will present work dealing with the understanding of formation and control of NOx, PAH and dioxins. During this work various techniques and methods have been applied, such as comprehen- sive industrial measurements, laboratory experiments, model development and application of Computational Fluid Dynamics (CFD). The main goal has been to reduce the environmental impact of ferroalloy plants, by means of improving the combustion processes done by introducing new charging routines and optimized fur- nace operations, instead of installing expensive gas treatment systems. The Norwegian obligations in accordance with the Gothenburg protocol are to reduce the NOx emissions by 30%, compared with the 1990 level within 2010. Measures developed in this work have r...

Based on requirements of circular economy and environmental protection for metallurgical slag reutilization, the research of hot metal dephosphorization with steel slag from converter is carried out in this paper. The effect of converter slag with different addition of CaO, Fe2O3 for the dephosphorizing rate is studied though analyzing the main phases of converter slag with SEM. The result indicates the main phases of converter slag are Ca2SiO4, RO phase, calcium ferrite and their combinations. The dephosphorizing rate is 29.41% while the converter slag mixes no CaO or Fe2O3, and the dephosphorizing rate rises as the increase of CaO and Fe2O3, then the dephosphorizing rate reaches 98.21% when the content of converter slag is 28%.

The study examines the dissolution process for the precipitates of the rare-earth carbonates and phosphates with a change in the concentration parameters of the system. The objective of the study is to determine the nature of the dissolution process at variable composition of the studied solutions. As a result of the theoretical base analysis, the qualitative and quantitative content of rare-earth metals in red sludge and phosphogypsum is presented, which governs the interest in this problem under consideration. The available techniques for extraction of rare-earth metals from red sludge and phosphogypsum have also been considered, their advantages and disadvantages are presented. A promising carbonate-alkali method for the extraction of rare-earth metals has been considered. Thermodynamic parameters of the system have been calculated to determine the possibility of the process. During the experiment the factors affecting the dissolution process have been examined: the carbonate ion...

Исследование рассматривает процесс растворения осадков карбонатов и фосфатов редкоземельных металлов при изменении концентрационных параметров системы. Задачей исследования является определение характера процесса растворения при различных составах изучаемых сред. В результате анализа теоретической базы представлены качественное и количественное содержание редкоземельных металлов в красном шламе и фосфогипсе, обуславливающие интерес к рассматриваемой проблеме. Также были рассмотрены доступные технологии извлечения редкоземельных металлов из красного шлама и фосфогипса, приведены их преимущества и недостатки. Рассматривался перспективный карбонатно-щелочной способ извлечения редкоземельных металлов. Для выявления возможности проведения процесса были рассчитаны термодинамические параметры системы. В ходе эксперимента рассмотрены факторы, влияющие на процесс растворения: концентрация карбонат-иона, природа катиона растворителя и катиона редкоземельного металла. В качестве анализируемых компонентов рассматривались карбонаты и фосфаты европия, гольмия и неодима. Карбонаты и фосфаты неодима, европия и гольмия растворялись в модельных растворах карбоната K 2 CO 3 с концентрацией от 0,2-4,5 моль/л до состояния равновесия. Полученные результаты показывают зависимость растворимости осадков редкоземельных металлов от природы растворителя и его концентрации. Данные представлены в виде изотерм растворимости. На основании экспериментальных данных рассчитаны значения степени извлечения редкоземельного металла в раствор. Для карбонатов неодима, европия и гольмия максимальная степень извлечения α max составила соответственно 72,8 %, 81,2 %, 83,0 % масс. В ходе эксперимента с растворением фосфатов лантаноидов получены следующие результаты: максимальная степень извлечения неодима -60,59 %, европия -51,66 %, гольмия -93,01 %. Ключевые слова: карбонат калия, изотерма, растворение, редкоземельные металлы, техногенное сырье, лантаноиды, шлам.

Al-Zn alloys are widely utilized in industries such as automotive, aircraft manufacturing, and ad-vanced military equipment due to their exceptional strength-to-weight ratio. Among various fab-rication methods, metal casting is a commonly used technique for producing structural compo-nents from these alloys. However, a significant challenge with metal casting is the reduction in mechanical properties compared to the base material before melting. This reduction highlights the need for research to identify the optimal casting conditions, particularly the casting temper-ature, which plays a crucial role in maintaining and potentially enhancing the material's mechan-ical properties. Aluminum alloy 7075, known for its high strength, was selected for investigation. According to the Al-Zn phase diagram, the melting point of aluminum alloy 7075, based on the weight percentage specified by the Standard Aluminum Association, is approximately 660°C. Ex-periments were conducted by varying the pouring temperature during casting in 30°C increments above this melting point. Specifically, the alloy was melted and cast at three different tempera-tures: 690°C, 720°C, and 750°C. The mold temperature was consistently maintained at 220°C to isolate the effects of the pouring temperature. Results indicate that increasing the casting tem-perature significantly affects the alloy's microstructure and mechanical properties. As the cast-ing temperature increases, the cooling rate decreases, leading to a finer grain structure. This finer grain size directly contributes to an increase in hardness, suggesting that higher casting temper-atures can enhance the mechanical properties of Al-Zn alloys. These findings emphasize the im-portance of precise control over casting temperatures to optimize the performance characteris-tics of aluminum alloy 7075 in high-strength applications.

There are many medium sized above-ground steel storage tanks in all industrial plants and under construction projects in Iran. Generally, most of these site-fabricated steel storage tanks are erected via conventional methods, which requires heavy capacity mobile cranes to lift, fit-up, and weld shell courses. In addition, another erection method, i.e. jack lifting erection method is globally well implemented in the past two decades, which may bear in many advantages over the conventional erection method. In this paper, the most significant advantages of this method for implementation in Sungun Copper Concentrator Plant (Phase III) is discussed briefly.

Nb O , visando a produção posterior de compósitos híbridos constituídos por polipropileno, pentóxido de nióbio e fosfato de cálcio em concentrações ideais, além de um nanomaterial com características antimicrobianas, como uma melhor alternativa econômica para enxertos ósseos aplicados à área odontológica. A escolha para os materiais base dos compósitos em estudo ocorreu, principalmente, devido a características específicas de cada um desses componentes, como a inerência biológica, a biocompatibilidade, a abundância no país e a bioatividade. Para a realização deste trabalho, foram confeccionados corpos de prova (CPs) com diferentes concentrações de Nb O (3.75%, 7.5%, 11.25% e 15%) em uma matriz de PP. Com o intuito de avaliar as características mecânicas, físicas e morfológicas, todos os CPs foram analisados através de ensaios mecânicos convencionais (tração, flexão e impacto) e da microscopia eletrônica de varredura (MEV).

Son zamanlarda, östenitik paslanmaz çeliklerin özellikle endüstride kullanımının hızla artması sonucu, bu tür çeliklerin kaynaklı birleştirilmeleri daha önemli hale gelmiştir. Paslanmaz çelikler, Tungsten İnert Gaz (TIG) ve Metal İnert Gaz (MIG) gibi gazaltı kaynak yöntemleri ile kolaylıkla kaynak edilebilmektedir. Özellikle ince kesite sahip paslanmaz çeliklerin birleştirilmesinde TIG kaynağı en uygun yöntem olup, yaygın olarak kullanılmaktadır. Bu çalışmada, östenitik paslanmaz çeliklerin gazaltı kaynak yöntemleri ile birleştirilmesinde kullanılan koruyucu gazların, birleştirilen paslanmaz çelik parçalarının mikroyapı ve mekanik özelliklerine etkisi, literatür bilgileri ışığında incelenmiştir. Koruyucu gaz olarak kullanılan argon (Ar) gazı içerisine karıştırılan hidrojen (H 2 ), karbondioksit (CO 2 ) ve azot (N 2 ) gazları, kaynak metalinin mikroyapısına dolayısıyla mekanik özelliklerine çok önemli bir şekilde etki ettiği vurgulanmaktadır.

Aim: This study investigates the dissolution of tantalite mineral from granitic pegmatite in Okpella,
Northern Edo State, Nigeria.
Study Design: Elemental and mineral composition analysis of tantalite ore sample from Okpella
was carried out using X-ray fluorescence and X-ray diffraction. Response Surface Methodology(RSM) and the shrinking core model were used in designing the study while the effects of
temperature, stirring speed, particle diameter, and mixed acids concentrations were investigated in
the dissolution rates of the mineral.
Duration of Study: 50 experimental runs were designed using RSM Central Composite Design
(CCD) to optimize variables including HF concentration (1-8 M), H2SO4 concentration (0.5-3 M),
temperature (32-82°C), stirring speed (0-500 rpm), and particle size (0.1-0.3 mm), with a constant
contact time of 240 minutes.
Methodology: Pulverized tantalite samples (0.1-0.3 mm) were reacted with varying concentrations
of hydrofluoric and sulphuric acids (1-8 M and 0.5-3.0 M, respectively) for 240 minutes, with stirring
speeds between 0-500 rpm and temperatures from 32 to 82°C. The mixture was stirred in a water
bath with 50 ml of mixed acids solution and 2 g of ore. After the reaction, the solution was
decanted, and the residual ore was washed, dried at 60 °C, and weighed. The difference between
the initial and final weights indicated the amount of undissolved tantalite ore.
Results: Ore characterization results revealed high concentration of tantalum (34.17%), iron
(12.55%), niobium (8.38%), and titanium (6.01%), with other elements present in smaller amounts.
Optimal conditions were found to be 8 M HF, 0.5 M H2SO4, 82°C, 500 rpm stirring speed, and 0.1
mm particle size, resulting in 97.28% dissolution of tantalite ore. Regression analysis demonstrated
model robustness with an F-value of 16.70 and a P-value of 0.0001, indicating HF concentration
and stirring speed as the most impactful factors. The model’s R² value of 0.9201 and adjusted R² of
0.8650 confirm its predictive accuracy. Analysis using the shrinking sphere model showed that film
diffusion control is the primary limiting step with t/τ=0.999, while reaction control resulted in slightly
lower conversion with t/τ=0.973, highlighting film diffusion as the main constraint but with high
conversion efficiency.
Conclusion: The findings from this investigation not only reveal the dissolution of tantalite ore
through a detailed experimental approach, identifying optimal conditions -8 M HF, 0.5 M H2SO4, 82
oC, 500 rpm stirring speed and 0.1 mm particle size- that achieve a 97.28% dissolution, but they
also enhance our understanding of mineral processing. These understanding are crucial for mineral
dissolution up scaling technologies in industrial applications, which will potentially leads to a more
efficient extraction method that could significantly reduce costs and environmental impacts in the
mining sector. This research could drive advancements in sustainable resource recovery and
contribute to sourcing of critical minerals.