Effect of Mill Type on Morphology of AA6013 Aluminium Powder

ABSTRACTIn conventional recycling method, metal chips are cast after pressing and melting in electric arc furnace. Material loss occurs during the recycling from liquid metal due to the several reasons. Direct recycling method which produces the aluminium powder from aluminium chips using mechanical mill can be an alternative to conventional recycling method. Thus material and energy losses, and labour cost will be reduced by direct recycling method without melting.In this study, the particle morphology of powder direct recycled from AA6013 aluminium alloy chips with cryogenic, disc and ball type grinders is investigated. Mechanical milling resulted flaky and irregular shaped AA6013 particles. It was ascertained that the chips did not break sufficiently in despite of the long duration milling mechanisms by ball mill. Cryogenic mill provides the energy required for milling mechanisms to act. Disc mill has the highest impact energy was determined. Consequently, efficiency of ball mill is lower than the efficiency of cryogenic and disc type mills. Shape factors of powders produced with ball and cryogenic mills were found greater than that of the powder produced by disc mill. Disc mill has the most efficient and effective impact energy which produces the smaller particles per minute, was determined.Keywords: Direct recycling method, powder production, scrap chips, aluminium alloy.

Cold metal transfer welding of AA1050 aluminum thin sheets

This study was aimed to investigate the welding parameters on mechanical behavior of 2 mm thick AA1050 sheet materials joined by cold metal transfer (CMT) method. Macro structural examination showed that decreasing heat input decreased the pore size in the weld metal. Tensile test was applied and failure occurred in heat affected zone of aluminum sheet metal. Maximum tensile strength was found in the sample with minimum heat input. Heat affected zone was observed explicitly in the sample produced with the maximum heat input. Decreasing joint gap affected the bending strength positively. Bending strength was found superior with maximum bonding line length. Keywords: CMT welding, mechanical characterization, AA1050

Effect of Mill Type on Morphology of AA6013 Aluminium Powder

ABSTRACTIn conventional recycling method, metal chips are cast after pressing and melting in electric arc furnace. Material loss occurs during the recycling from liquid metal due to the several reasons. Direct recycling method which produces the aluminium powder from aluminium chips using mechanical mill can be an alternative to conventional recycling method. Thus material and energy losses, and labour cost will be reduced by direct recycling method without melting.In this study, the particle morphology of powder direct recycled from AA6013 aluminium alloy chips with cryogenic, disc and ball type grinders is investigated. Mechanical milling resulted flaky and irregular shaped AA6013 particles. It was ascertained that the chips did not break sufficiently in despite of the long duration milling mechanisms by ball mill. Cryogenic mill provides the energy required for milling mechanisms to act. Disc mill has the highest impact energy was determined. Consequently, efficiency of ball mill is lower than the efficiency of cryogenic and disc type mills. Shape factors of powders produced with ball and cryogenic mills were found greater than that of the powder produced by disc mill. Disc mill has the most efficient and effective impact energy which produces the smaller particles per minute, was determined.Keywords: Direct recycling method, powder production, scrap chips, aluminium alloy.

Determination of Hardness of Pre-Aged AA 6063 Aluminum Alloy by Means of Artificial Neural Networks Method

A lot of experiments must be conducted in order to find an appropriate technology for the calculation of strength of the materials, which wastes both man power and money. For this reason artificial neural networks (ANNs) have been used to search the optimum technology proper for pre-aged AA 6063 aluminum alloy. In this study, ANNs were used to compare experimental results and test data were used for teaching of the ANNs. This paper examines the changes in the hardness of AA 6063 alloys when heat treated at different pre-aging treatments. The alloy was solution treated for 1 hour at 525±3 °C and quenched in water. After quenching, samples were subjected to five different pre aging times, 2 hours, I day, 3 days, 7 days. On the other hand, some specimens were not pre-aged. Artificial age temperatures were selected as 160 °C and 180 °C. The hardness values of these under-aged alloys were measured. When the pre-aging time was 7 days, the hardness values of the specimens increased. An excellent correlation was found between experimental hardness results and ANNs hardness results

Bazı anti-enflamatuar ilaçların yük transfer komplekslerinin incelenmesi

Bu tezin, veri tabanı üzerinden yayınlanma izni bulunmamaktadır.ÖZET Anahtar Kelimeler : Elektron donör akseptör kompleksleri, antienflamatuar, TCNE, DDQ,p~Kloranil, Etofenomat, Etodolak ve Naproxen. Bu çalışmanın amacı antienflamatuar ilaçlar olan Etofenomat, Etodolak ve Naproksen'in electron donör akseptör komplekslerini nasıl oluşturduğunu incelemektir. Elektron akseptörler olan TCNE, DDQ ve p-Kloraml ile elektron donörler olan Etofenomat, Etodolak ve Naproksen'in elektron donör akseptör kompleksleri spektrofotometrik olarak incelendi. Kompleks stokiometrileri Job Metodu, komplekslerin denge sabitleri Benesi-Hildebrand denklemi ve termodinamik sabitleri Van't Hoff denklemi ile hesaplandı. Etofenomat - TCNE kompleksi 670 nm de maksimum absorpsiyon verdi. Kompleksin denge sabiti 2,219 Lmol"1, termodinamik sabitleri AH: -769,6 cal mol"1, AS: -10,10 cal mol"1 ve AG °: -465,64 cal mol"1 dir. Etodolak - TCNE kompleksi 597 nm de maksimum absorpsiyon verdi. Kompleksin denge sabiti 0,775 Lmol"1, termodinamik sabitleri AH: -2752,2 cal mol"1, AS: -12,01 cal mol"1 ve AG °: 150,4 cal mol'1 dir. Naproksen - TCNE kompleksi 611 nm de maksimum absorpsiyon verdi. Kompleksin denge sabiti 0,721 Lmol"1, termodinamik sabitleri AH: -891 cal mol"1, AS: -9,25 cal mol"1 ve AG °: 192 cal mol"1 dir. Etofenomat - DDQ kompleksi 763 nm de maksimum absorpsiyon verdi. Kompleksin denge sabiti 6,2 Lmol"1, termodinamik sabitleri AH: -3660 cal mol"1, AS: -14,5 cal mol"1 ve AG °: -1065,91 cal mol"1 dir. Naproksen - DDQ kompleksi 703 nm de maksimum absorpsiyon verdi. Kompleksin denge sabiti 6,53 Lmol", termodinamik sabitleri AH: -2378 cal mol"1, AS: -13,46 cal mol"1 ve AG °: -1 105 cal mol"1 dir. Etofenomat -/»-Kloranil kompleksi 575 nm de maksimum absorpsiyon verdi. Kompleksin denge sabiti 2,54 Lmol"1, termodinamik sabitleri AH: -1548 cal mol"1, AS: -14,85 cal mol"1 ve AG °: -546,4 cal mol"1 dir. Etodolak - p-Kloranil kompleksi 536 nm de maksimum absorpsiyon verdi. Kompleksin denge sabiti 5,45 Lmol"1, termodinamik sabitleri AH: -1336 cal mol"1, AS: -9,88 cal mol"1 ve AG °: -993,94 cal mol"1 dir. Naproksen -p-Kloranil kompleksi 554 nm de maksimum absorpsiyon verdi. Kompleksin denge sabiti 5,4 Lmol"1, termodinamik sabitleri AH: -1048 cal mol"1, AS: -11,74 cal mol"1 ve AG °: -985,2 cal mol"1 dir. XIIEXAMINING CHARGE TRANSFER COMPLEXES OF SOME ANTİ-İNFLAMATORY DRUGS SUMMARY Keywords : Electron donor acceptor complexes, anti-inflammatory, TCNE, DDQ, p-Chloranil, Etofenomat, Etodolac, Naproxene. The purpose of this study is to examine how Etofenomat, Etodolac and Naproxene which are anti-inflamatory drugs form electron donor acceptor complexes. Electron donor acceptor complexes of Etofenomat, Etodolac, Naproxene as electron donors with TCNE, DDQ, /7-Chloranil as electron acceptors have been examined spectrophotometricly. Stoichiometries of the complexes were calculated by Job's method. Equilibrium constants of the complexes were calculated by Benesi- Hildebrand equation. Thermodynamic constants of the complexes were calculated by Van't Hoff equation. EDA complexes of Etofenomat - TCNE gave a maximum absorption at 670 nm. Equilibrium constant of the complex is 2,219 L mole"1, thermodynamic constants of the complex; AH: -769,6 cal mole"1, AS: -10,10 cal mole"1 and AG °: -465,64 cal mole"1. EDA complexes of Etodolac - TCNE gave a maximum absorption at 597 nm. Equilibrium constant of the complex is 0,775 L mole"1, thermodynamic constants of the complex; AH: -2752,2 cal mole"1, AS: -12,01 cal mole"1 and AG °: 150,4 cal mole"1. EDA complexes of Naproxene - TCNE gave a maximum absorption at 611 nm. Equilibrium constant of the complex is 0,721 L mole"1, thermodynamic constants of the complex; AH: -891 cal mole"1, AS: -9,25 cal mole"1 and AG °: 192 cal mole"1. EDA complexes of Etofenomat - DDQ gave a maximum absorption at 763 nm. Equilibrium constant of the complex is 6,2 L mole"1, thermodynamic constants of the complex; AH: -3660 cal mole"1, AS: -14,5 cal mole"1 and AG °: -1065,91 cal mole"1. EDA complexes of Naproxene - DDQ gave a maximum absorption at 703 nm. Equilibrium constant of the complex is 6,53 L mole"1, thermodynamic constants of the complex; AH:-2378 cal mole"1, AS:-13,46 cal mole"1 and AG °: -1105 cal mole"1. EDA complexes of Etofenomat - /7-Chloranil gave a maximum absorption at 575 nm. Equilibrium constant of the complex is 2,54 L mole"1, thermodynamic constants of the complex; AH: -1548 cal mole"1, AS: -14,85 cal mole"1 and AG °: -546,4 cal mole"1. EDA complexes of Etodolac - /7-Chloranil gave a maximum absorption at 536 nm. Equilibrium constant of the complex is 5,45 L mole"1, thermodynamic constants of the complex; AH: -1336 cal mole, AS: -9,88 cal mole"1 and AG °: -993,94 cal mole"1. EDA complexes of Naproxene -/?-Chloranil gave a maximum absorption at 554 nm. Equilibrium constant of the complex is 5,4 L mole"1, thermodynamic constants of the complex; AH: -1048 cal mole"1, AS: -11,74 cal mole"1 and AG °: -985,2 cal mole"1. x

Soğuk Metal Transfer Kaynağı ile Birleştirilmiş AA7075-Galvanizli Çelik Çiftinin Korozyon Direncinin İncelenmesi

msufbdKorozyon, metalin çevresi ile arasındakikimyasal reaksiyonların bir sonucu olarak bozulmasıdır. Fakat korozyon, öncedentahmin edilebilir, bazı durumlarda önemli ölçüde yavaşlatılabilir veyaönlenebilir. Bu çalışmada, pek çok konstrüksiyonun oluşturulmasında kullanılanimalat yöntemlerinden biri olan kaynak çeşitlerinden soğuk metal transferkaynağı ile üretilen AA7075-galvanizli çelik bağlantılarda galvanik korozyonoluşumunun ve farklı bağlantıların gerilme dayanımına etkisi incelenmiştir.Alüminyum ve çelik çifti diğer kaynak yöntemleriyle birleştirilmesinin zorolduğu bir çifttir. Bu yöntem ile birleştirilme sağlanmıştır. Bu çalışmada, bağlantıda oluşacak korozyon incelenmiştir. Sonuç olarak, kaynak sırasındaartan ısı girişi galvanik korozyonu olumsuz yönde etkiledi ve malzemeçözünmesini arttırdığı tespit edilmiştir.Corrosion is the degradation ofthe metal as a result of chemical reactions with its surroundings. However, corrosion can be predicted, in some cases significantly slowed down orprevented. In this study, the effect of galvanic corrosion formation on the tensilestrength of AA7075-galvanized steel joints produced by cold metal transferwelding, which is one of the manufacturing methods used in forming manyconstructions, was investigated. The aluminum and steel pair are difficult tocombine with other welding methods. Joining is provided by this method.Corrosion in this joining was investigated in this article. As a result, increased heat input during welding adversely affected galvanic corrosion andincreased material dissolution.54064

New Non-Destructive Test: Micro Defect Detection by Bacterial Cell

msufbdMicro production is crucial for scientific, technologic and industrial areas. As used non-destructive testing methods are insufficient for determining these kinds of micro defects. With this new technique micro defects on surface like fissures, cracks and voids could be determined by applying bacterial cells on the surface to be examined. The considerably small dimensions, high penetration abilities, mobilities, adhesive properties, fluorescence properties, sensitivities to magnetic and electric field and reproducibility of bacterial cells create the base of this technique.Mikro boyutta üretim bilimsel, teknolojik ve endüstriyel alanlarda oldukça önemli bir yer tutmaktadır. Hali hazırda kullanılan tahribatsız muayene yöntemleri bu tip mikro hataların tespitinde yetersiz kalmaktadır. Makalede açıklanan yeni teknikle bakteri hücreleri, incelenmek istenen yüzeye uygulanarak yüzeye açık olan mikro boyuttaki yarıklar, çatlaklar ve boşluklar tespit edilebilmektedir. Bu tekniğin temelini bakterilerin oldukça küçük boyutları, yüksek penetrasyon kapasiteleri, hareket edebilirlikleri, tutunabilirlikleri, floresans özellikleri, elektrik ve manyetik alana duyarlılıkları ve tekrar üretilebilir olmaları gibi özellikleri oluşturmaktadır.54467