Mechanism for corrosion protection of β-TCP reinforced ZK60 via laser rapid solidification

It remains the primary issue to enhance the corrosion resistance of Mg alloys for their clinical applications. In this study, beta-tricalcium phosphate (beta-TCP) was composited with Mg-6Zn-1Zr (ZK60) using laser rapid solidification to improve the degradation behavior. Results revealed rapid solidification effectively restrained the aggregation of beta-TCP, which thus homogenously distributed along grain boundaries of a-Mg. Significantly, the uniformly distributed beta-TCP in the matrix promoted the formation of apatite layer on the surface, which contributed to the formation of a compact corrosion product layer, hence retarding the further degradation. Furthermore, ZK60/8 beta-TCP (wt. %) composite showed improved mechanical strength, as well as improved cytocompatibility. It was suggested that laser rapidly solidified ZK60/8 beta-TCP composite might be a potential materials for tissue engineering.