Abstract:
Magnesium alloy AZ91, known for its lightweight nature, biocompatibility, and controlled
biodegradability, is a promising material for orthopedic implants. However, faster corrosion
in a physiological environment remains a challenge. This work investigates Electrical Discharge Machining (EDM) with copper and brass electrodes in a kerosene dielectric to optimize
the surface roughness, hardness, and corrosion resistance of AZ91. Electrochemical deposition
of copper and brass coatings was also performed to modulate the degradation rate. Surface assessment through Scanning Electron Microscopy (SEM) and X-ray Diffraction (XRD) indicated
that optimizing EDM parameters greatly improved the surface quality, which was characterized
by less roughness and higher hardness. Of the coatings, copper exhibited better corrosion resistance, which slowed down the degradation of AZ91 in simulated body fluid (SBF). Therefore,
this combination of EDM with electrochemical deposition opens up the possibility of developing
patient-specific implants with controlled degradation rates, which ensures mechanical support
during healing and avoids follow-up surgeries. This work paves the way for next-generation
bioresorbable implants, effectively providing a bespoke solution to orthopedic applications integrating precision machining and surface engineering techniques.
