Mehmet TOPUZ, Burak DİKİCİ, Mehmet GAVGALI

Hidroksiapatit ile Biyo-fonksiyonelleştirilmiş Titanyum-esaslı Yapı İskelelerinin Toz Metalurjisi Tekniği ile Üretimindeki Zorluklar

Son zamanlarda titanyum ve alaşımları gelişmiş mekanik, yüzey ve biyolojik özellikleri nedeniyle araştırmacıların ilgisini çekmektedir. Araştırmacılar, özellikle sağlık alanında yeni malzemeleri araştırmakta ve belki de malzeme tasarımı, düşük Young modülü sergilemesinden dolayı, en önemli kriterdir. Bu kriterler içerisinde en çok tercih edilen ise hidroksiapatit (HA) ile güçlendirilmiş kompozit malzemelerdir. Gözenekli malzemeler, Young modülünü kemiğe yakın sergiledikleri için tercih edilmektedirler. Çalışmanın amacı, titanyum/hidroksiapatit (Ti/HA) kompozit yapı iskelelerinin üretiminde karşılaşılan sorunlar ve çözüm önerileri üzerinde durulacaktır. Bunlar kısaca; porojen giderimi, farklı sinterleme fırınlarının kullanılması, sinterleme atmosferi, malzeme kalınlığı, aşırı veya yetersiz presleme sonucu çatlak oluşumu-yayılması ve kalıp doldurma sırasında porojenlerin aglomerasyonu. Ar gazı atmosferi altında dikey tüp fırınların kullanılmasının, yatay tüp fırınların ve farklı atmosferlerin (vakum veya Ar gazı) kullanımına kıyasla başarılı sonuçlar verdiği kanıtlanmıştır. Başarıyla üretilen kompozit iskelelerde makro gözeneklerin yanı sıra yetersiz boyun büyümesi ve yetersiz pres basıncından kaynaklanabilecek mikro gözeneklerin de oluştuğu sonucuna varılmıştır. Ek olarak, sonuçlar bi-modal (makro/mikro gözeneklilik) gözenek yapılarının olası biyomateryal kullanımında kemik dokusu yönlenmesine katkıda bulunabileceğini göstermiştir.

Anahtar Kelimeler:

Toz metalürjisi (TM), Titanyum, Hidroksiapatit, Kompozit doku iskelesi, Gözenekli malzeme.

Challenges in the Production of Titanium–based Scaffolds Bio–functionalized with Hydroxyapatite by Powder Metallurgy Technique

Recently, titanium and its alloys have remarkable interest for researchers due to their advanced mechanical, surface and biological properties. Researchers are investigating new materials, especially in the field of health, and perhaps material design is the most important criteria that exhibit the low Young’s modulus of bone. Along with these criteria’s most preferred are composite materials reinforced with hydroxyapatite (HA). Porous materials are preferred because they exhibit Young’s modulus close to the bone. The aim of the study, the problems encountered in the production of titanium/hydroxyapatite (Ti/HA) composite scaffolds and the solutions will be emphasized. These are briefly; porogen removal, usage of different sintering furnaces, sintering atmosphere, material thickness, crack formation-propagation as a result of excessive or insufficient pressing pressure, and agglomeration of porogens during mold filling. It has been proven that the use of vertical tube furnaces under the Ar gas atmosphere has successful results compared to the use of horizontal tube furnaces and different atmospheres (vacuum or Ar gas). It has been concluded that in the composite scaffolds that have been successfully produced, micropores are formed as well as macropores, which may result from insufficient neck growth and pressing pressure. In addition, results showed that bi-modal (macro/micro porosity) pore structures may contribute to bone tissue orientation in possible biomaterial use.

Keywords:

Powder metallurgy (PM), Titanium, Hydroxyapatite, Composite scaffolds, Porous materials.,

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