Microstructure, mechanical property and corrosion behavior of interpenetrating (HA+β-TCP)/MgCa composite fabricated by suction casting.

The novel interpenetrating (HA+β-TCP)/MgCa composites were fabricated by infiltrating MgCa alloy into porous HA+β-TCP using suction casting technique. The microstructure, mechanical properties and corrosion behaviors of the composites have been evaluated by means of scanning electron microscopy (SEM), X-ray diffraction (XRD), mechanical testing, electrochemical and immersion tests. It was shown that the composites had compact structure and the interfacial bonding between MgCa alloy and HA+β-TCP scaffolds was very well. The ultimate compressive strength of the composites was about 500-1000 fold higher than that of the original porous scaffolds, and it still retained quarter-half of the strength of the bulk MgCa alloy. The electrochemical and immersion tests indicated that the corrosion resistance of the composites was better than that of the MgCa matrix alloy, and the corrosion products of the composite surface were mainly Mg(OH)2, HA and Ca3(PO4)2. Meanwhile, the mechanical and corrosive properties of the (HA+β-TCP)/MgCa composites were adjustable by the choice of HA content.
(© 2013.)