Çinko-Esaslı Kaplamanın Kataforez Prosesi ile Desteklenerek Kaplama Özelliklerinin Geliştirilmesi: Asitlik ve Kaplama Kalınlığının Kaplama Kalitesine Etkisi

Öz

Bu çalışmada, otomobil sektöründe sıklıkla kullanılan iki sıcak-dövme döküm malzeme, uygun maliyetli iki kaplama formunun (çinko + kataforez) birleştirilmesiyle düşük mikronlarda geliştirilmiş korozyon performansına sahip döküm elemanları üretmek için kullanılmıştır. Araştırma kapsamında, GGG40 döküm malzemeleri üzerine önce alkali (Zn, Zn-Fe, Zn-Ni) veya asidik (Zn, Zn-Ni) ortamda 5-8 µm veya 12-15 µm çinko-kaplama, ardından 20- 25 µm kataforez-kaplama uygulanmıştır. Karakterizasyon için mürekkep, hogabom, şok, pull-off adhezyon, su direnci, tuz sisi, taş çarpma, çevrimsel-korozyon ve scab-korozyonu performans testleri yapılmıştır. Ayrıca çinko-kaplama kalınlığı ve fosfat-kristal görünümü, x-ışını kırınım laminografi cihazında ve taramalı elektron mikroskobunda değerlendirilmiştir. Çekme dayanımları, 171 ve 433 psi arasında çekme yapışma testi ile belirlenmiştir. Alkali ve asidik ortamlarda çinko-kaplı parçaların kaplama kalınlıkları 5,88-7,18 µm ve 12,10-12,96 µm aralığında ölçülmüştür. Karakterizasyon sonuçlarına göre; alkali ortam altında tüm çinko-esaslı-kaplamalardan sonra uygulanan kataforez-kaplamanın gerekli kaliteyi ve korozyon korumasını sağlamadığı, buna karşılık kataforez-kaplamadan önce asidik ortam altında kaplanan döküm parçaların uygun korozyon performansı gösterdiği sonucuna varılmış, dolayısıyla istenilen özelliklere sahip düşük-maliyetli kaplamaların yapılabileceği belirlenmiştir.

Anahtar Kelimeler

• Döküm malzemeler
• kataforez kaplama
• korozyon performansı
• asidik/alkali çinko-esaslı kaplamalar.

Proje Numarası

3180632

Enhancement of Coating Features by Supporting Zinc-Based Coating with Cataphoresis Process: Effect of Acidity and Coating Thickness on the Coating Quality

Öz

In this work, two hot-forged cast materials that are often used in the automobile sector were employed to produce cast elements with enhanced corrosion performance at low microns by combining two forms of cost-effective coatings (zinc + cataphoresis). In the context of the investigation, firstly 5-8 µm or 12-15 µm zinc-coating in an alkaline (Zn, Zn-Fe, Zn-Ni) or an acidic (Zn, Zn-Ni) environment, followed by 20-25 µm cataphoresis-coating were performed on GGG40 cast-parts. Ink, hogabom, shock, pull-off adhesion, water resistance, salt spray, stone impact, cyclic-corrosion, and scab-corrosion performance tests were implemented for characterization. In addition, the zinc-coating thickness and the phosphate-crystal appearance were evaluated in the x-ray diffraction laminography instrument and the scanning electron microscope. The tensile strengths were determined by the pull-off adhesion test between 171 and 433 psi. The coating thicknesses of zinc-coated parts in alkaline and acidic environments were assigned in the range of 5.88-7.18 µm and 12.10-12.96 µm. Due to the characterization results; it was deduced that the cataphoresis-coating after all zinc-based-coatings under alkaline medium did not afford the required quality and corrosion protection, while cast parts coated under acidic medium before cataphoresis-coating gave appropriate corrosion performance, thus the low-cost coatings could be performed with the eligible properties.

Anahtar Kelimeler

• Cast materials
• cataphoresis coating
• corrosion performance
• acidic/alkaline zinc-based coatings.

Destekleyen Kurum

TÜBİTAK

Proje Numarası

3180632

Teşekkür

This study was supported as part of the TÜBİTAK 3180632 project carried out by Uzman Cataphoresis Surface Coating Industry Trade Inc., and the authors would like to thank TÜBİTAK and Uzman Cataphoresis Surface Coating Industry Trade Inc.

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