Degradation behaviors of Mg alloy wires/PLA composite in the consistent and staged dynamic environments

Fully degradable poly lactic acid based composite reinforced with 20 vol% magnesium alloy wires (MAWs) is prepared for weight bearing bone fracture healing. The degradation behaviors of the composite in the consistent and staged dynamic environments are investigated. The results suggest that dynamic loading would overall accelerate the degradation of the composite. As the loading magnitude increases from 0.2 MPa to 1 MPa or frequency from 0.5 Hz to 2.5 Hz, the degradation rate goes up. Under the staged dynamic loading condition, the degradation behaviors of the composite would show staged change determined by the dynamic loading condition at each stage. A numerical model is proposed to systematically depict the mechanical performances of the composite in the consistent and staged dynamic environments. The composite could theoretically provide sufficient stabilization for >8 weeks in a feasible dynamic environment to achieve successful bone fracture healing.