Publication: Toz enjeksiyon kalıplama tekniği ile üretilen b4c seramikler için besleme stoğunun hazırlanması, reolojik ve bağlayıcı giderme özelliklerinin belirlenmesi
Abstract
TOZ ENJEKSİYON KALIPLAMA TEKNİĞİ İLE ÜRETİLEN B4C SERAMİKLER İÇİN BESLEME STOĞUNUN HAZIRLANMASI, REOLOJİK VE BAĞLAYICI GİDERME ÖZELLİKLERİNİN BELİRLENMESİ Bor karbür (B4C), günümüz ileri teknoloji seramikleri arasında önemli bir yere sahip olup, elmas ve kübik bor nitrürden sonra dünyanın en sert üçüncü malzemesidir. B4C’nin üstün özelliklerinden dolayı birçok uygulama alanında aşındırıcı, kumlama nozülü, zımpara ve zırh malzemesi olarak kullanılmaktadır. Karmaşık şekilli malzemelerin üretiminde Toz Enjeksiyon Kalıplama (TEK) tekniği, endüstriyel açıdan oldukça avantajlı bir yöntemidir. Bu tez çalışmasında, B4C tozu ve çeşitli polimer bağlayıcılar besleme stoğu hazırlamak için kullanılmıştır. Tozun morfolojisi SEM ile analiz edilmiştir. Hacimce %50-60 oranında değişen toz ilaveleri ile B4C ve polimer bağlayıcılarla karıştırılarak besleme stokları elde edilmiştir. Besleme stoklarının reolojik özelliklerinin incelenmesi için reometre cihazı kullanılarak farklı sıcaklıklarda ölçümleri yapılmıştır. Besleme stokları, TEK için temel gereksinimlerden biri olan psödoplastik akış davranışı sergilemektedir. Besleme stoğu ayrıca yüksek toz ilavelerinde sıcaklığa yüksek hassasiyet göstermektedir. Kalıplanan numuneler değişik sıcaklıklarda 10 saat boyunca heptan içerisinde bağlayıcıları gidermiştir. Bağlayıcı giderme işlemi sonrası numunelerin kırık yüzeylerinin SEM görüntüleri alınmıştır.
DETERMINATION OF RHEOLOGIC AND DEBINDING PROPERTIES, FEEDSTOCK PREPARATION FOR B4C CERAMICS PRODUCED BY POWDER INJECTION MOLDING TECHNIQUE Boron carbide (B4C) has an important place among today's high-tech ceramics that is the world's third hardest material after diamond and cubic boron nitride. Boron carbide is used as abrasive, sanding nozzle, abrasive and armor material in many application fields due to its superior properties. Powder Injection Molding (PIM) method is a very advantageous method in terms of industrial in the production of mixed shaped materials. In this study, B4C powder and polymeric binders were used to feedstocks. The morphology of the powder was analyzed by scanning electron microscopy. B4C powder was mixed with a polymeric binder with a powder loading volume from 50% to 60% to obtain feedstock. The flow properties of the B4C feedstock were evaluated using a rheometer at different temperatures. It was found that feedstocks exhibits a pseudoplastic flow behavior, which is one of the main requirements for PIM. Feedstock is also shown to be highly sensitive to temperature at high powder loading. Molded samples were debinded in heptane during 10 hours at various temperatures. After debinding, SEM images of the fractured surfaces of the samples were taken.
DETERMINATION OF RHEOLOGIC AND DEBINDING PROPERTIES, FEEDSTOCK PREPARATION FOR B4C CERAMICS PRODUCED BY POWDER INJECTION MOLDING TECHNIQUE Boron carbide (B4C) has an important place among today's high-tech ceramics that is the world's third hardest material after diamond and cubic boron nitride. Boron carbide is used as abrasive, sanding nozzle, abrasive and armor material in many application fields due to its superior properties. Powder Injection Molding (PIM) method is a very advantageous method in terms of industrial in the production of mixed shaped materials. In this study, B4C powder and polymeric binders were used to feedstocks. The morphology of the powder was analyzed by scanning electron microscopy. B4C powder was mixed with a polymeric binder with a powder loading volume from 50% to 60% to obtain feedstock. The flow properties of the B4C feedstock were evaluated using a rheometer at different temperatures. It was found that feedstocks exhibits a pseudoplastic flow behavior, which is one of the main requirements for PIM. Feedstock is also shown to be highly sensitive to temperature at high powder loading. Molded samples were debinded in heptane during 10 hours at various temperatures. After debinding, SEM images of the fractured surfaces of the samples were taken.