Study on mechanical and degradation behavior of Zn-Mn-xMg alloys under coupling effects of stress and SBF

Zinc-based implants will be subjected to combination of physiological corrosive media and stress during service in vivo. In this study, the mechanical and degradation behavior of Zn-Mn-xMg alloys under coupling effects of stress and simulated body fluid (SBF) were investigated. As a result, the ultimate tensile strength of Zn-Mn-xMg alloys decreased and incline to brittle fracture under the condition of slow strain rate tensile test in SBF. In addition, at a slower strain rate (1 x 10(-6) s(-1)), the stress corrosion cracking susceptibility value will increase with the rise of Mg content. The immersion test under different compressive stresses shows that the corrosion will be inhibited under high pressure stress (50 MPa) compared with the lower one (10 MPa). The residual compressive strength of Zn-0.8Mn-xMg alloys decreases after immersion. A dense oxide layer could be induced with the increase of compressive stress, and it would inhibit the corrosion of the Zn-0.8Mn-xMg matrixes. These results indicate that Zn-0.8Mn-xMg alloys are expected to be a promising biodegradable material for biomedical applications.