Az91 Magnezyum Alaşımının Mikro Ark Oksidasyonunda Elektrolit Bileşiminin Etkileri
Az91 Magnezyum Alaşımının Mikro Ark Oksidasyonunda Elektrolit Bileşiminin Etkileri
Dosyalar
Tarih
2013-01-06
Yazarlar
Gözüaçık, Namık Kemal
Süreli Yayın başlığı
Süreli Yayın ISSN
Cilt Başlığı
Yayınevi
Fen Bilimleri Enstitüsü
Institute of Science and Technology
Institute of Science and Technology
Özet
Bu çalışmada, farklı konsantrasyonlarda organik kimyasal ilaveli silikat ve fosfat esaslı elektrolitlerde voltaj kontrollü olarak mikro ark oksidasyon işlemi uygulanan AZ91 magnezyum alaşımı numunelerin yüzey özellikleri, mekanik özellikleri ve korozyon özellikleri incelenmiştir. AZ91 magnezyum alaşımına, silikat ve fosfat esaslı elektrolitlere Hexamethylenetetramine (HMTA), TRIS hydroxymethyl aminomethane (THAM), Gliserol gibi bazı organik kimyasallardan düşük ve yüksek konsantrasyonlarda ilave edilerek yapılan mikro ark oksidasyon işlemi sonucunda elde edilen kaplamaların yapısal ve morfolojik karakterizasyonu; yüzey incelemeleri, kesit incelemeleri, XRD analizleri, kaplama kalınlığı ölçümleri, yüzey pürüzlülüğü ölçümleri, mikro sertlik ölçümleri, çizik deneyleri ve elektrokimyasal korozyon deneyleri ile gerçekleştirilmiştir. Silikat ve fosfat esaslı elektrolitlere yapılan organik kimyasal ilaveleri genel olarak kaplama kalınlığını azaltmış, yüzey pürüzlülüğünü düşürmüştür. Silikat esaslı elektrolite yapılan organik kimyasal ilaveleri kaplamaların ortalama por boyutu ve por yoğunluğunu azaltmasına rağmen korozyon direncini geliştirmemiştir. Fosfat esaslı elektrolite düşük ve yüksek konsantrasyonlarda yapılan THAM ve HMTA ilaveleri kaplamaların ortalama por boyutu ve por yoğunluğunu azaltarak korozyon direncini arttırmıştır.
In this study, surface properties, mechanical properties and corrosion properties of AZ91 magnesium alloy samples, which micro arc oxidation treatment is applied on them as voltage-controlled in silicate and phosphate based electrolytes with addition of organic chemicals in varied concentrations are investigated. Structural and morphological characterization of coatings obtained by applying micro arc oxidation process to AZ91 magnesium alloy with addition of some organic chemicals such as Hexamethylenetetramine (HMTA), TRIS hydroxymethyl aminomethane (THAM) and Glycerol in low and high concentrations to silicate and phosphate based electrolytes are performed by surface investigations, cross-section investigations, XRD analysis, coating thickness measurements, surface roughness measurements, micro hardness measurements, scratch tests and electrochemical corrosion tests. The addition of organic chemicals to silicate and phosphate based electrolytes generally reduces coating thickness and surface roughness. Although the addition of organic chemicals to silicate based electrolyte in low and high concentrations reduces mean pore size and pore density of coatings, it has not improved corrosion resistance. The addition of THAM and HMTA to phosphate based electrolyte in low and high concentrations has improved corrosion resistance by reducing mean pore size and pore density of coatings.
In this study, surface properties, mechanical properties and corrosion properties of AZ91 magnesium alloy samples, which micro arc oxidation treatment is applied on them as voltage-controlled in silicate and phosphate based electrolytes with addition of organic chemicals in varied concentrations are investigated. Structural and morphological characterization of coatings obtained by applying micro arc oxidation process to AZ91 magnesium alloy with addition of some organic chemicals such as Hexamethylenetetramine (HMTA), TRIS hydroxymethyl aminomethane (THAM) and Glycerol in low and high concentrations to silicate and phosphate based electrolytes are performed by surface investigations, cross-section investigations, XRD analysis, coating thickness measurements, surface roughness measurements, micro hardness measurements, scratch tests and electrochemical corrosion tests. The addition of organic chemicals to silicate and phosphate based electrolytes generally reduces coating thickness and surface roughness. Although the addition of organic chemicals to silicate based electrolyte in low and high concentrations reduces mean pore size and pore density of coatings, it has not improved corrosion resistance. The addition of THAM and HMTA to phosphate based electrolyte in low and high concentrations has improved corrosion resistance by reducing mean pore size and pore density of coatings.
Açıklama
Tez (Yüksek Lisans) -- İstanbul Teknik Üniversitesi, Fen Bilimleri Enstitüsü, 2012
Thesis (M.Sc.) -- İstanbul Technical University, Institute of Science and Technology, 2012
Thesis (M.Sc.) -- İstanbul Technical University, Institute of Science and Technology, 2012
Anahtar kelimeler
AZ91 magnezyum alaşımı,
Elektrolit,
Fosfat,
Gliserol,
HMTA,
Korozyon direnci,
Mikro ark oksidasyon,
Por,
Silikat,
THAM,
AZ91 magnesium alloy,
Electrolyte,
Phosphate,
Glycerol,
Hexamethylenetetramine,
Corrosion resistance,
Micro arc oxidation,
Pore,
Silicate,
TRIS hydroxymethyl aminomethane