Manufacturing, mechanical and microstructural characterization of AZ91D magnesium alloy for biomedical applications

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Tezin Türü: Yüksek Lisans

Tezin Yürütüldüğü Kurum: Orta Doğu Teknik Üniversitesi, Mühendislik Fakültesi, Mühendislik Bilimleri Bölümü, Türkiye

Tezin Onay Tarihi: 2015

Öğrenci: SAİD MURAT KAYHAN

Danışman: ZAFER EVİS

Özet:

In this study, the microstructural and mechanical properties of the Mg-based implant samples prepared via powder metallurgy route were investigated. Moreover, the biological response of the Mg-based implant samples was investigated. AZ91D Mg alloy discs with smooth and textured surfaces were manufactured under compaction pressures of 25 and 40 MPa at 150⁰C. They were then sintered at 380⁰C for 30 and 150 mins. The microstructural evaluation was conducted through SEM and light microcopy images. As compaction pressure increased, the relative densities of the discs increased (0.57-0.67%) as well as the diametral tensile strength (2.55-3.01 MPa) and Vickers micro-hardness values (13.5-84.1 HV2). Extended sintering time did not affect the relative densities while increased the hardness of the discs. It was also found that sintering time did not affect significantly the diametral tensile strength. However, the discs with textured surface had lower relative density. The sintered discs had higher mechanical and relative density values than the unsintered ones. The validity of relative density measurements was provided by image processing technique and finite element method. The Mg alloy discs showed no toxicity in methylthiazolyldiphenyl-tetrazolium (MTT) assay. It was also seen that the discs with a textured surface with channels had more cell viability than the disc with a smooth surface.