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.

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.

Evaluation of patients with fibrotic interstitial lung disease: Preliminary results from the Turk-UIP study

OBJECTIVE: Differential diagnosis of idiopathic pulmonary fibrosis (IPF) is important among fibrotic interstitial lung diseases (ILD). This study aimed to evaluate the rate of IPF in patients with fibrotic ILD and to determine the clinical-laboratory features of patients with and without IPF that would provide the differential diagnosis of IPF. MATERIAL AND METHODS: The study included the patients with the usual interstitial pneumonia (UIP) pattern or possible UIP pattern on thorax high-resolution computed tomography, and/or UIP pattern, probable UIP or possible UIP pattern at lung biopsy according to the 2011 ATS/ERSARS/ALAT guidelines. Demographics and clinical and radiological data of the patients were recorded. All data recorded by researchers was evaluated by radiology and the clinical decision board. RESULTS: A total of 336 patients (253 men, 83 women, age 65.8 +/- 9.0 years) were evaluated. Of the patients with sufficient data for diag-nosis (n=300), the diagnosis was IPF in 121 (40.3%), unclassified idiopathic interstitial pneumonia in 50 (16.7%), combined pulmonary fibrosis and emphysema (CPFE) in 40 (13.3%), and lung involvement of connective tissue disease (CTD) in 16 (5.3%). When 29 patients with definite IPF features were added to the patients with CPFE, the total number of IPF patients reached 150 (50%). Rate of male sex (p<0.001), smoking history (p<0.001), and the presence of clubbing (p=0.001) were significantly high in patients with IPE None of the women <50 years and none of the men <50 years of age without a smoking history were diagnosed with IPE Presence of at least 1 of the symptoms suggestive of CTD, erythrocyte sedimentation rate (ESR), and antinuclear antibody (FANA) positivity rates were significantly higher in the non-IPF group (p<0.001, p=0.029, p=0.009, respectively). CONCLUSION: The rate of IPF among patients with fibrotic ILD was 50%. In the differential diagnosis of IPF, sex, smoking habits, and the presence of clubbing are important. The presence of symptoms related to CTD, ESR elevation, and EANA positivity reduce the likelihood of IPF

LAZERLE KAYNAK İSLEMİNDE KAYNAK PARAMETRELERİNİN KAYNAK KALİTESİ ÜZERİNDEKİ ETKİLERİNİN İNCELENMESİ

Lazer kaynak yöntemi geleneksel kaynak yöntemlerine göre birçok üstün özelliklere sahiptir. Düsük ısı girdisi, dar bir ITAB olusumu, düsük kalıntı gerilmeleri ve çarpılmalar, yüksek kaynak hızı, derin nüfuziyet, kusursuz kaynak profili, yüksek yapısal dayanım, otomasyonla birlestirme lazer kaynagının saglamıs oldugu öncelikli avantajlardır. Bunun yanı sıra yüksek verimlilik ve ekonomiklik, düsük hata oranı diger faydalı özelliklerindendir. Bu çalısmada 50x40 mm ebatlarında 2,0 mm kalınlıgında AISI 304 paslanmaz çelik malzemeler lazer kaynagıyla alın alına birlestirilmis, bu malzemelerden elde edilen 20x80 mm ebatlarındaki numunelerde metalografik incelemeler yapılmıs, kaynak bölgesinin sertligi ölçülmüs, TS 282 EN 910 standartlarında belirtilen esaslarla üç nokta egme deneyi yapılmıstır. Elde edilen sonuçlara göre, kaynak bölgelerinde malzeme kalınlıgı (2 mm) boyunca tam nüfuziyet elde edilmistir ve katılasan kaynak metali anahtar deligi formundadır. Kaynak hızının artmasıyla kaynak metali genisliginin azaldıgı tespit edilmistir. Katılasan kaynak metalinde östenit fazı ile tane ve alt tane sınırlarında olusan ferrit fazı tespit edilmistir. Kaynak hızı arttıkça geçis bölgesi genisliginin azaldıgı tespit edilmistir. ITAB'ta kaynak metalinden esas metale dogru uzanan yatay dogrultuda ferrit bantları tespit edilmistir. Kaynak parametreleriyle (lazer gücü, kaynak hızı) ferrit bantlarının olusumları arasında iliskiler tespit edilmistir. Sertlik, esas metalden kaynak metaline dogru artıs göstermistir. Isı arttıkça kaynak metali sertligi ve egme dayanımı genel anlamda arttıgı görülmektedir