Effects of extrusion and heat treatment on the mechanical properties and biocorrosion behaviors of a Mg–Nd–Zn–Zr alloy

Mechanical properties at room temperature and biocorrosion behaviors in simulated body fluid (SBF) at 37 °C of a new type of patented Mg–3Nd–0.2Zn–0.4Zr (hereafter, denoted as JDBM) alloy prepared at different extrusion temperatures, as well as heat treatment, were studied. The mechanical properties of this magnesium alloy at room temperature were improved significantly after extrusion and heat treatment compared to an as-cast alloy. The results of mechanical properties show that the yield strength (YS) decreases with increasing extrusion temperature. The tensile elongation decreases a little while the ultimate tensile strength (UTS) has no obvious difference. The yield strength and ultimate tensile strength were improved clearly after heat treatment at 200 °C for 10 h compared with that at the extrusion state, which can be mainly contributed to the precipitation strengthening. The biocorrosion behaviors of the JDBM alloy were studied using immersion tests and electrochemical tests. The results reveal that the extruded JDBM alloy and the aging treatment on the extruded alloy show much better biocorrosion resistance than that at solid solution state (T4 treatment), and the JDBM exhibited favorable uniform corrosion mode in SBF.

► A new type of patented Mg–2.0–4.0Nd–0.1–0.5Zn–0.3–0.6Zr (JDBM) alloy was designed for biomedical applications, avoiding potential risk caused by Al or heavy rare earth elements.
► The JDBM alloy exhibits good strength, excellent elongation and corrosion resistance after hot extrusion and heat treatment.
► The corrosion mode of the JDBM alloy is uniform corrosion, different from the serious local pitting mode of other commercial Mg alloys, such as AZ91.