Microstructure and characteristics of the metal–ceramic composite (MgCa‐HA/TCP) fabricated by liquid metal infiltration

Abstract

In this article, a novel MgCa alloy-hydroxyapatite-tricalcium phosphate (HA/TCP) composite was fabricated using the liquid alloy infiltration technique. The feasibility of the composite for biomedical applications was studied through mechanical testing, electrochemical testing, immersion testing, and cell culture evaluation. It was shown that the composite had a strength about 200-fold higher than that of the original porous HA/TCP scaffold but retained half of the strength of the bulk MgCa alloy. The corrosion test indicated that the resulting composite exhibited an average corrosion rate of 0.029 mL cm⁻² h⁻¹ in the Hank's solution at 37°C, which was slower than that of the bulk MgCa alloy alone. The indirect cytotoxicity evaluation revealed that 100% concentrated (i.e., undiluted or as-collected) extract of the MgCa-HA/TCP composite showed significant toxicity to L-929 and MG63 cells (p < 0.05). In contrast, the diluted extracts with 50 and 10% concentrations of the MgCa-HA/TCP composite exhibited a similar degree of cell viability (p > 0.05), equivalent to the grade I cytotoxicity of the standard ISO 10993-5: 1999.

Microstructure, mechanical property and corrosion behaviors of interpenetrating C/Mg-Zn-Mn composite fabricated by suction casting

“…But from the Fig. 10, the pH value remained mostly a constant after 50 hours, and the similar results were obtained in the other immersion tests [12,29,40].…”

“…That is, the C/Mg-Zn-Mn composite shows a great improvement in the strength and the elongation in comparison with the original porous carbon scaffold. MgCa-HA/TCP composite were investigated in our previous study, that the crushing of ceramic foams is based on bending of the struts [29]. The interpenetration of the Mg-Zn-Mn alloy stabilizes the ceramic struts and partially prevents strut bending, resulting in a major improvement of the mechanical properties of the ceramic scaffold.…”

“…Compared with the Mg-Zn-Mn alloy and porous carbon and other biomedical Mg composite [6,11,21,29], the mechanical property and corrosion behaviors of the C/Mg-Zn-Mn composite can satisfy the requirement of implant materials, so this composite is a very promising candidate for bone substitute.…”

“…In our previous study, the corrosion rate of the MgCa-HA/TCP composite fabricated by liquid metal infiltration was slower than that of the bulk MgCa alloy alone. And the diluted extracts with 50 and 10% concentrations of the resulting composite exhibited grade I cytotoxicity to L-929 and MG63 cells [29]. However, few attempts have been made so far to combine porous carbon with Mg alloys to prepare a new biomedical material.…”

Structure, mechanical property and corrosion behaviors of (HA + β-TCP)/Mg–5Sn composite with interpenetrating networks

“…8c, e and f, that local corrosion happens along the interface between Mg-5Sn alloy and the scaffolds. In our previous study, severe local corrosion along the interface between MgCa alloy and the HA + β-TCP scaffolds was also found [40]. The ceramic/metal interface has the capability of forming a galvanic couple in the electrolyte and the electrically conducting scaffold becomes the noble member.…”