Date

2015

Author

Tahmasebifar, Aydin

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In this study, the effect of manufacturing conditions (i.e. compaction pressure, sintering temperature and time) on physical, mechanical and electrochemical properties of Mg alloy discs as samples of biomedical implants prepared using powder forming technology were investigated. The main motivation of this study was to achieve the manufacturing of porous and micro-surface textured Mg-based biomedical implants with good mechanical and electrochemical properties. A Box-Behnken and Full Factorial experimental design was used in experimentation. Relative densities of the plates were obtained experimentally. They varied from 69.7±1% to 81.5±4%. According to ANOVA (Analysis of variances) test, manufacturing conditions did not affect the relative density significantly except the compaction pressure level. The bending strength was in the range of 30.3±2 MPa and 53.7±1 MPa. Compaction pressure led to an increase in the bending strength while sintering temperature and time decreased. Electrochemical tests were conducted using Hank’s solution, DMEM (Dulbecco's Modified Eagle's Medium) and 10% FBS (Fetal Bovine Serum)+DMEM. The lowest and the highest corrosion potentials were measured in Hank’s and 10% FBS+DMEM solutions, respectively. Pitting corrosion was detected on the surface of Mg alloy discs. In Hank’s solution, pitting corrosion was observed more than DMEM and 10% FBS+DMEM. The discs with smooth surfaces also showed lower corrosion resistance than the discs with porous and micro-textured surfaces in the presence of FBS. It was concluded that the manufacturing of porous and micro-surface textured Mg based biomedical implant using powder forming process was reasonable due to the convenience of near net shape production with sufficient material properties. Also, the cell culture studies showed that micro texture and roughness positively affected cell adhesion, proliferation and osteogenic activity. AZ91D-Mg alloy plates showed good cytocompatibility with higher cell proliferation compared to control groups at each incubation time period.

Subject Keywords

Materials, Biodegradable products., Powder metallurgy., Biomedical materials., Magnesium alloys.

URI

http://etd.lib.metu.edu.tr/upload/12619248/index.pdf
https://hdl.handle.net/11511/25185

Collections

Graduate School of Natural and Applied Sciences, Thesis