Microstructure and characteristics of interpenetrating β-TCP/Mg–Zn–Mn composite fabricated by suction casting

A novel interpenetrating β-TCP/Mg–Zn–Mn composite was fabricated by infiltrating Mg–Zn–Mn alloy into porous β-TCP using suction casting technique. The microstructure, mechanical property and corrosion behaviors of the composite have been evaluated by means of scanning electron microscopy (SEM), X-ray diffraction (XRD), mechanical testing, electrochemical and immersion test. It was shown that the composite had a compact structure and the interfacial bonding between Mg–Zn–Mn alloy and β-TCP scaffold was very well. The composite had an ultimate compressive strength of 140 ± 20 MPa, which is near with the natural bone (2–180 MPa) and about 1000-fold higher than that of the original porous β-TCP scaffold, and it still retained about two fifths of the strength of the bulk Mg–Zn–Mn alloy. The electrochemical and immersion tests indicated that the corrosion resistance of the composite was better than that of the Mg–Zn–Mn matrix alloy, and the corrosion products on the composite surface were mainly Mg(OH)2, Ca3(PO4)2 and HA.