In-vitro corrosion and biocompatibility properties of heat treated Mg-4Y-2.25Nd-0.5Zr alloy

In this study, corrosion and biocompatibility behaviour of Mg-4Y-2.25Nd-0.5Zr alloy (Mg-Y-Nd-Zr) was investigated. The pre-alloyed powder of Mg-Y-Nd-Zr was processed using powder metallurgy (PM) method, followed by further heat treatment at 250 °C for 12 h. The microstructural features of as-sintered and heat treated Mg-Y-Nd-Zr alloy showed secondary phases like Mg₂₄Y₅ and Mg₄₁Nd₅ in α-Mg matrix. In heat treated samples, the alloy showed improved compressive strength and hardness. The hardness and compressive strength was better for the heat treated Mg-Y-Nd-Zr alloy samples (54 ± 2 HV and 243 ± 30 MPa) compared to heat treated pure Mg samples (44 ± 5 HV and 129 ± 11 MPa). This is because of rearrangement of the secondary phases in the matrix. The corrosion current density of Mg-Y-Nd-Zr alloy samples reduced by 45% (82.2 μA/cm² for heat treated and 149.3 μA/cm² for as-sintered) after heat treatment indicating its better corrosion resistance than as-sintered samples. Both heat treated and as-sintered alloy exhibited good biocompatibility and therefore the Mg-Y-Nd-Zr alloy is a potential candidate for biodegradable implants.