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Toz metalurjisi tekniği ile üretilen kobalt esaslı süperalaşımlarda element ilavelerinin mikroyapı ve mekanik özelliklere etkisi

Bu çalışmada, toz metalurjisi (T/M) tekniği ile element tozlarından üretilen Stellite 6 süperalaşım malzemelerin mikroyapı ve mekanik özelliklerine Fe ve B elementlerinin etkisi incelenmiştir. Yüksek saflıktaki element tozlarından farklı oranlarda Fe ve B içeriğine sahip karışım tozlar hazırlanmıştır. Hazırlanan karışımlar T/M yöntemi ile şekillendirilip farklı sıcaklıklarda sinterlenmişlerdir. Sinterleme işlemlerinin başarısı yoğunluk ölçümleri ile değerlendirilmiştir. Mikroyapısal karakterizasyon X-ışınları analizi (XRD), taramalı elektron mikroskobu (SEM) incelemeleri ve enerji dağılımı spektrometresi (EDS) ile gerçekleştirilmiştir. Mekanik özelliklerin karakterizasyonu için mikrosertlik ölçümleri yapılmıştır. Stellite 6 numunelerinin mikroyapısında, kullanılan Cr tozunun iri boyutlu olması nedeniyle iri boyutlu karbürlerin oluştuğu tespit edilmiştir. B ilavesi ile birlikte bağıl yoğunluk değerleri bir miktar artmıştır. B ile birlikte Fe elementinin ilave edilmesiyle bağıl yoğunluk önemli ölçüde artış göstermiştir.

Anahtar Kelimeler:

Stellite 6, B ilavesi, Fe ilavesi, yoğunluk, mikroyapı, sertlik

The Effect of element additions on the microstructure and the mechanical properties of cobalt based superalloys produced via powder metallurgy technique

In this study, the effect of Fe and B elements on the microstructure and mechanical properties of Stellite 6 superalloy materials produced from elemental powders by powder metallurgy (P/M) technique was investigated. Powder mixtures contained different Fe and B content were prepared from high purity elemental powders. The prepared powder mixtures were shaped by P/M method and then sintered at various temperatures. The success of sintering operations was determined by density measurements. Microstructural characterization was carried out with X-ray diffraction analysis (XRD), scanning electron microscope (SEM) and energy dispersive spectrometry (EDS). Microhardness measurements were conducted for to characterize mechanical properties. Due to large particle size of the used Cr powder coarse carbides formed in the microstructure of Stellite 6 samples. Relative density values increased slightly with B addition. Relative density was increased dramatically by the addition of Fe element with B.

Keywords:

Stellite 6, B addition, Fe addition, density, microstructure, hardness,

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