Process mechanics and surface integrity by high-speed dry milling of biodegradable magnesium–calcium implant alloys

Compared to conventional metallic implant materials, biodegradable Mg–Ca alloys are attractive orthopedic biomaterials that avoid negative stress shielding and revision surgeries. However, the process mechanics and surface integrity by high-speed dry milling Mg–Ca0.8 are poorly understood. Key findings of the synergistic experimental and numerical study are: (a) Mg–Ca0.8 alloy is sensitive to strain rate and adiabatic softening; (b) high-speed dry milling can be safely performed using PCD tools with process characteristics of lamella structured chips and slight flank build-up; and (c) machined surface integrity is characterized by low roughness, highly compressive residual stress, increased microhardness, and microstructure without phase changes.