In situ decomposition of Ti2AlN promoted interfacial bonding in ZnAl-Ti2AlN biocomposites for bone repair

Abstract

In this study, in situ decomposition of Ti2AlN was used to obtain strong interfacial bonding in Zn7Al-Ti2AlN composites prepared via laser melting. During the preparation process, the Al atoms in Ti2AlN could diffuse out of the lattice due to the weak bonding between Al and Ti, followed by easily diffusing into the liquid Zn7Al matrix. Consequently, the diffused Al could bond with the Al in Zn7Al matrix owing to their inherent chemical affinity, leading to a strong interfacial bonding in Zn7Al-Ti2AlN composites. This significantly improved the load transfer ability and prohibited the motion of dislocations in the composites. As a result, the hardness and compressive strength of Zn7Al-Ti2AlN composites were enhanced from 74 HV and 155 MPa to 80 HV and 205 MPa, respectively, which were more suitable for bone repair application. What's more, the composites also showed improved accelerated degradation and cytocompatibility.