NANO WC KOMPOZİTLERDE Fe-Ni ORANIN MİKROYAPI VE MEKANİK ÖZELLİKLERE ETKİSİ

Günümüzde geniş bir kullanım alanına sahip olan WC takviyeli metal matrisli kompozitler (MMK) önemli mühendislik malzemelerindendir. Bu kompozit malzemeler kesici takım malzemesi endüstrisinin çok önemli bir bölümünü oluşturmaktadır. Co, sinterlenmiş karbürler için en çok kullanılan bağlayıcı matris fazıdır. Dünya üzerinde kısıtlı tedariği nedenli fiyat dalgalanması ve özellikle karjiyonik etkileri nedeniyle Co'ın alternatifler ile değiştirilmesi bilimsel literatürde yoğun bir ilgi konusudur. Bu durum alternatif bağlayıcı matris arayışlarını daha da arttırmaktadır. Mevcut çalışmaların farklı bileşikler ve alaşımlara odaklandığı görülmektedir. Bu çalışmada, ucuz ve zararlı etkileri azaltışmış MMK malzeme üretimi amaçlanmıştır. WC, Fe, Ni ve C tozları kullanılarak toz metalurjisi yöntemi ile farklı kimyasal bileşime sahip MMK malzemeler üretilmiştir. Deneysel çalışmalarda tozlar homojen karıştırma işlemi yapıldıktan sonra, eksenel ve soğuk izostatik olarak preslenmiş ve basınçsız argon ortamında sinterlenmişlerdir. Üretilen numunelerin mikroyapı (yoğunluk, faz) ve mekanik (sertlik, elastisite modülü, kırılma tokluğu) özellikleri deneysel ve ampirik olarak incelenmiştir. Yapılan çalışmada bağlayıcı faz olarak farklı oranlarda Fe, Ni ve C katkısının mikroyapı ve mekanik özelliklere olan etkisi araştırılmıştır. Fe ve Ni katkıları için kritik bir oranın olduğu ve tespit edilen miktarın üstünde katılmasının kırılma tokluğunu azalttığı tespit edilmiştir. En uygun kimyasal bileşim, mikroyapı ve mekanik özelliklere göre belirlenmiştir.

Anahtar Kelimeler:

Toz Metalurjisi, Metal Matrisli Kompozitler, Mekanik Özellikler.

THE EFFECT OF Fe-Ni RATIO ON MICROSTRUCTURE AND MECHANICAL PROPERTIES IN NANO WC COMPOSITES

WC-content metal matrix composites (MMC), which have a wide usage area today, are essential engineering materials. These composite materials constitute a vital part of the cutting tool material industry. Co is the most commonly used binder matrix phase material for sintered carbides. Replacing Co with alternatives is a subject of intense interest in the scientific literature due to the price fluctuation caused by limited supply globally and especially its carcinogenic effects. This situation further increases the search for alternative binding matrices. Current studies seem to focus on different compounds and alloys. In this study, it is aimed to produce cheap MMC materials with reduced detrimental effects. MMC materials with different chemical compositions were produced by powder metallurgy method using WC, Fe, Ni, and C powders. In the experimental studies, the powders were pressed axially and cold isostatically and sintered in an unpressurized argon environment after homogeneous mixing. The produced samples' microstructure (density, phase) and mechanical (hardness, modulus of elasticity, fracture toughness) properties were investigated experimentally and empirically. The study investigated the effect of Fe, Ni and C additives in different ratios as the binding phase on the microstructure and mechanical properties. It has been determined that there is a critical ratio for Fe and Ni additives, and the addition of above the determined amount reduces the ampirical fracture toughness. The chemical composition with the most suitable content in the samples was determined according to the microstructure and mechanical properties.

Keywords:

Powder Metallurgy, Metal Matrix Composites, Mechanical Properties,

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