Production and investigation of biodegradable implant by powder metallurgy method

In this study, porous biodegradable Mg, Zn, Fe alloys and TCP specimens for use as tissue scaffold material in tissue engineering applications were produced by the powder metallurgy based space holder method. Also, for use (as screw, plate, etc.) in biodegradable orthopedic implant applications, dense Mg, Zn and Fe, austenite Fe alloys and TCP specimens were produced by the traditional powder metallurgy method, and dense Fe-based specimen was produced by the powder injection molding (PIM) method. Density values of cylindrical green specimens and sintered specimens were determined using the mass/volume relationship by the geometric (gravimetric) method. Within the scope of characterization studies, the mechanical properties and microstructures of the specimens were analyzed. The mechanical properties of the specimens were determined by compression test and non-destructive ultrasonic testing method. Electrochemical corrosion properties were investigated in simulated body fluid. In addition, the amount of released metallic ions and the rate of biodegradation were investigated in simulated body fluid by the static immersion test. X-ray diffraction (XRD) analysis was performed to determine the phase structure of the specimens. The total pore (open and closed) amounts of the porous specimens were determined using the mass/volume relationship (geometric method). At the end of the study, specimens with different percentages of pores ranging from 68% to 83% were produced for tissue engineering applications. It was seen from the comparison of mechanical properties that Fe alloys with dense austenitic structures have the highest modulus of elasticity. In the biodegradability investigations, the weight change of Fe, Mg and Zn alloys was within the expected values. The amounts of released Fe, Zn and Mg ions were lower than the toxic threshold value for the human body. It was seen from the results of the XRD analyses that the phase structure of the elements in the alloys was preserved. Also, it was observed from the results of the electrochemical corrosion characteristics that the corrosion rates of Mg-Zr alloy from among Mg alloy, Fe-Co alloy from among Fe alloys, and Zn-Fe alloy from among Zn alloys were low. Keywords: Biomaterial, Tissue Engineering, Biodegradable Implants, Powder Metallurgy