Self-healing coatings have been developed as smart surface coatings for Mg and its alloys to retain local corrosion from the coating damages. In this study, we prepared dicalcium phosphate dihydrate (DCPD) coating on biomedical Mg, and found that the artificial scratches in DCPD coating can be efficiently sealed by anti-corrosive products in both Hank's and normal saline (NS) solutions. Besides, the in-depth study revealed that DCPD was served as not only a physical barrier but also a self-healing agent, demonstrating an autonomous self-healing coating without embedded extra corrosion inhibitors. Moreover, Hank's solution provided foreign-aid film-forming ions to promote self-healing behavior. The findings might offer new opportunities for further studies and applications of efficient self-healing coatings on biodegradable Mg implants.

Zn and Zn-based alloys exhibit biosafety and biodegradation, considered as candidates for biomedical implants. Zn-0.02wt.Mg (Zn-0.02Mg), Zn-0.05wt.Mg (Zn-0.05Mg), and Zn-0.2wt.Mg (Zn-0.2Mg) wires (Φ 0.3mm) were prepared for precision biomedical devices in this work. With the addition of Mg in Zn-xMg alloys, the grain size decreased along with the occurrence of Mg₂Zn₁₁ at the grain boundaries. Hot extrusion, cold drawing, and annealing treatment were introduced to further refining the grain size. Besides, the hot extrusion and cold drawing improved the tensile strength of Zn-xMg alloys to 240-270MPa while elongation also increased but remained under 10. Annealing treatment could improve the elongation of Zn alloys to 12 -28, but decrease the tensile strength. Furthermore, Zn-xMg wires displayed an increase in degradation rate with Mg addition. The findings might provide a potential possibility of Zn-xMg alloy wires for biomedical applications.

The effect of composition of welding wires on the interfacial microstructure and the bonding strength of Babbitt alloys and steel substrate has been studied. A cladding of Sn-based Babbitt alloys was obtained on the surface of medium carbon steel by MIG arc brazing. The microstructure of Babbitt alloys and the interfacial microstructure of the interface between Babbitt alloys and steel substrate have been systematically investigated. The bonding strength of Babbitt and steel substrate has been collected according to the destructive testing method of the bimetallic bonding strength of sliding bearing. Among the three samples, the BW8-4 and steel substrate without no SnSb segregation had the highest bonding strength (83.07 MPa).The reason for the enhancement of the bonding strength was discussed. The IMC layers were harder than the α-Sn matrix so that they can effectively prevent the crack between generating and expanding at the joint part. Then, the bonding strength can be enhanced a lot. However, in samples obtained by BW11-6 and BW8-8, the segregated SnSb phase near the junction which was hard and fragile would result in the concentration of stress. And the SnSb would also lead to the occurrence of brittle fracture in the segregation. So that the bonding strength had been greatly reduced.