نرجس اصغري نژادبلوچي

In recent years, magnesium-based alloys have been widely noticed by researchers and manufacturers in terms of structural applications due to their good strength-to-weight ratio, low density (1.738 g/cm^3) and good machinability. However, the simultaneous effect of the corrosive environment and the mechanical loading of these alloys in the human body are easily affected by corrosion fatigue and stress cracking. In this research, the fatigue behavior of Magnesium alloy WE54 before and after immersion in simulated body fluid (SBF) was studied. For this purpose, alloy characterization was done using scanning electron microscope (SEM) equipped with elemental analysis (EDS) and optical microscope (OM). Measuring the mechanical properties of magnesium alloy WE54 was investigated through tensile and compressive tests before and after immersion in SBF solution. According to tensile and compressive tests, the maximum and minimum ultimate tensile and compressive strength of the alloy before immersion were from 278.26 MPa and 390.64 MPa to 190.427 MPa and 282.69 MPa, respectively. After 336h has passed from the degradation time in SBF solution. The eva‎luation of the biodegradability of the alloy was done by immersion test, including the eva‎luation of the weight loss and degradation rate of the alloy and the amount of changes in the pH of the SBF solution. The bioactivity of the alloy was eva‎luated in SBF solution and the sediments formed were identified by SEM and elemental analysis. According to the fatigue test, the fatigue life of the Magnesium alloy WE54 before immersion in the simulated solution of the body under constant stress of 15 MPa is 3598 cycles, While the fatigue life of the said alloy has reached 453 cycles after 336h immersion in the simulated solution of the body under the mentioned constant stress. Examining the fracture surface of the sample by SEM shows that the origin of the fatigue crack before immersion is micro-pores and defects, While, corrosion pits and corrosion cracks are the main reasons for the formation of the initial fatigue crack after immersion. Also, the results obtained from practical work were eva‎luated and compared with theoretical calculations.

زيست سازگاري , زيست تخريب¬پذيري , خوردگي , خستگي , خستگي ناشي از خوردگي , محلول شبيه سازي شده بدن , آلياژ همگن شده منيزيم WE54

Homogeneous Magnesium WE54 , Bio-compatibility , biodegradability , corrosion , fatigue , Corrosion fatigue , Simulated Body Fluid

Narjes Asghari Nezhad

Dr. Eivani