Dimensional Analysis-Based Modelling of Weight Loss and Degradation Rate of Topologically Ordered Functionally Graded Iron–Hydroxyapatite–Zinc Composite Biomaterial Using Buckingham’s π Theorem

Over past few years, degradable biomedical implants have replaced permanent orthopaedic implants. The compatibility and functionality of biodegradable implants are greatly influenced by their degradation rate. Development of topologically-ordered functionally graded iron–hydroxyapatite–zinc (Fe–HAp–Zn) composite biomaterial with tailorable degradation rate could be a feasible solution to the problems associated with using any single biodegradable metal. However, in order to attain the desired degradation rate, a mathematical model needs to be developed for predicting the degradation rate. In this study, models for prediction of weight loss and corrosion rate have been suggested. For this, Fe–HAp–Zn composite samples were fabricated using 3D printing, microwave sintering, and casting. Static immersion tests and potentiodynamic polarisation studies were conducted to evaluate degradation characteristics. Then, mathematical models were developed for predicting weight loss and corrosion rate, utilizing this experimental data. The values predicted with developed models were found to be in strong concurrence with the experimental results.