Kil Çamuru Örneklerinin Akış Özellikleri ile Seramik Ham/Pişmiş Ürünlerin Özellikleri Arasındaki İlişki

Bu çalışmada, slip döküm ile üretilen ham ve sinterlenmiş ürünlerde istenilen özellikleri sağlamak için ESC-3 kili kullanılarakhazırlanan çamura çeşitli dispersantların (Dolapix PC-67, Dolapix SPC 7, Darvan CN, Darvan A821 ve Na2SiO3), akış özelliklerineetkileri araştırıldı. Çamurun akış eğrileri dikkate alınarak, en uygun dispersantın Dolapix PC-67 olduğu ve dozajın da ~% 0.1 olduğubelirlendi. Daha sonra çamur, aynı deney şartlarında ve sırasıyla ağırlıkça % 0, 0.03, 0.1 ve 1.0 Dolapix PC-67 dozajları kullanılarakçubuk şeklindeki numuneler hazırlandı. Elde edilen ham numuneler kurutulduktan sonra 1200°C'de sinterlendi. Ham ve sinterlenmişnumunelere bazı fiziksel ve mekanik testler uygulanmış, ayrıca SEM ve XRD kullanılarak mikro yapıları, kristallikleri ve ikincil fazoluşumları incelenmiştir. Elde edilen sonuçlardan bazıları şöyledir: (i) Çamura dispersant ilave edilmesi, slip döküm ile elde edilen ham ve sinterlenmiş ürünlerin fiziksel ve mekanik özellikleri üzerinde olumlu bir etkiye sahip olmuştur. (ii)Slip döküm yöntemiyle kilçamuru hazırlanırken kullanılacak dispersant miktarının optimum değerinin belirlenmesi önemli bir husustur. Ancak ford cup ile eldeedilen akışkanlık eğrileri ve sonrasında elde edilen ham/sinterlenmiş ürün özelliklerine göre şu söylenebilir: Seramik döküm çamurlarında akış süresinin en düşük (yani akışkanlığın en yüksek) olduğu dispersant dozajında, ham ve sinterlenmiş ürünlerinfiziksel/mekanik özelliklerinin de daima en iyi olacağı anlamına gelmemektedir. (iii) Farklı dispersant dozajlarında hazırlanan çamurdanelde edilen ham ve pişmiş ürünlerin fiziksel ve mekanik özellikleri ile çamurun akışkanlık eğrisi arasındaki ilişkiyi SEM görüntüleriyleortaya koymak pek mümkün değildir.

The Relationship between the Flow Properties of Clay Slurry Samples and the Properties of Ceramic Green/Sintered Products

This study investigated the effects of various dispersants (Dolapix PC-67, Dolapix SPC 7, Darvan CN, Darvan A821 and Na2SiO3) onthe flow properties of slurry prepared using ESC-3 clay to find the optimum dispersant type and dispersant dosage to produce therequired properties in green and sintered products produced by slip casting. By considering the flow curves of slurry, it was determinedthat the most suitable dispersant was Dolapix PC-67 and the dosage was ~0.1%. Afterwards, the slurry was prepared in bar-shapedsamples keeping the same experimental conditions and using Dolapix PC-67 dosages of 0, 0.03, 0.1 and 1.0 wt. %. The resulting greenbody samples were dried and sintered at 1200°C. Some physico-mechanical tests were applied to both the green and sintered samples,as well as investigating their microstructure, crystallinity and secondary phase formations using SEM and XRD. Some of the resultsobtained were as follows: (i) adding dispersant to the slurry had a positive effect on the physical and mechanical properties of the greenand sintered products obtained by slip casting. (ii) Determination of the optimum dispersant dosage used in the ceramic slurry by slipcasting is an important factor. When the properties of the green/final products and their flow curves measured by Ford cup wereconsidered, it can be said that the dispersant dosage at which the shortest flow duration was obtained did not always correspond to thebest results for the physico-mechanical properties of green/final products. (iii) The relationship between the green and sintered samples prepared from slip casting using different dispersant dosages, and the flow curves of these slips, could not be observed from their SEMimages.

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