Improvements in phase stability and densification of β-tricalcium phosphate bioceramics by strontium-containing phosphate-based glass additive

β-tricalcium phosphate (β-TCP), which transforms to α-TCP at around 1125 °C, is characterized by poor sinterability. In this study, for the first time strontium-containing phosphate-based glass (SPG) was used as a sintering additive for β-TCP, which was sintered at 1250 °C. The results indicated that the SPG additive allowed for liquid-state sintering of β-TCP, thereby noticeably promoting the densification of β-TCP bioceramics. In the sintering process SPG reacted with β-TCP, and the metal ions from SPG were substituted for the calcium ions of β-TCP. The SPG additive effectively inhibited the phase transformation of β-TCP to α-TCP in the bioceramics. The compressive strength of porous β-TCP bioceramics was markedly increased by introducing 10 wt% SPG. The SPG is considered as an effective sintering additive to improve the phase stability and mechanical strength of porous β-TCP bioceramics.