Toz metalurjisi ile üretilen biyomedikal Ti-Nb esaslı alaşımlarda Nb ilavesinin mikroyapı ve mekanik özelliklere etkisi

Öz

İnsan sert doku ( kemik gibi) biyo-implant malzemeleri için Ti-Nb esaslı alaşımlar biyo-uyumları, mekanik özellikleri, korozyon dirençleri gibi özellikleri açısından umut vadeden malzemelerdir. Bu çalışmada, Nb ilavesinin, Ti-Nb ikili alaşımının mikroyapı ve mekanik özellikleri üzerine etkisinin incelenmesi amacıyla saf Ti, Ti-16Nb, Ti-26Nb alaşımları geleneksel toz metalürjisi yöntemi ile üretilmiştir. Sinterlenmiş numunelerin mikroyapısal gelişimleri ve faz analizleri optik mikroskop, SEM, EDS, XRD teknikleri kullanılarak belirlenmiştir. Sinterlenen Ti-Nb alaşımlarının mikroyapısının widmanstatten α+β yapısından oluştuğu gözlemlenmiştir. Nb içeriğinin ağırlıkça %16’dan %26’ya artışı ile alaşımın mikrosertlik değeri 430 HV’den 327 HV’ye, eğme mukavemeti 1403 MPa’dan 1168 MPa’a ve elastik modül 103 GPa’dan 90 GPa’a düşmüştür. Mikroyapı da ise β-fazı miktarı artarken, taneler incelmiştir. Elde edilen sonuçlar, toz metalürjisi ile üretilmiş Ti-Nb alaşımlarının, klinik uygulamalarda en yaygın kullanılan Ti-6Al-4V alaşımının yerine tercih edilebileceğini göstermektedir.

Anahtar Kelimeler

• Biyomedikal Ti-Nb alaşımları,Toz metalurjisi,Elastik modül,Biyo-implant malzeme

Effect of Nb addition on microstructural and mechanical properties of Ti-Nb based alloys produced by powder metallurgy

Abstract

Ti-Nb based alloys are promising materials in terms of material properties, such as biocompatibility, mechanical properties and corrosion resistance for human hard tissuse (such as bone) bio implant materials. Present study focused on the effects of Nb addition on the microstructure and mechanical properties of Ti-Nb binary alloy. For this purpose, pure Ti, Ti-16Nb, Ti-26Nb alloys were produced by conventional powder metallurgy (PM) method. Microstructural development and phase analysis of sintered samples were determined by using optical microscopy, SEM, EDS, XRD techniques. It was observed that microstructures of sintered Ti-Nb alloys consist of widmanstatten α+β structure. With an increasing in the content of Nb (from 16 to 26 wt. %), the micro-hardness values of the alloys decrease from 430 HV to 327 HV, the bending strength of the alloys decreases from 1403 MPa to 1168 MPa and the elastic modulus of the alloys decreases from 103 GPa to 90 GPa. Also, it is worth noting that, finer grains achieved and the amount of the β-phase in the microstructure is increased with increasing Nb content. Results of the experimental works showed that PM Ti-Nb alloys could be offered as candidate materials for clinical practice applications as an alternative to Ti-6Al-4V alloy.

Keywords

• Biomedical Ti-Nb alloys,Powder metallurgy,Elastic modulus,Bio-implant material

Kaynakça

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