Morphology and quantitative characteristics of ceramic phase in Ti-HA composites with ≤20vol% HA

Abstract

This paper studied Ti-HA composites with low volume fractions of hydroxyapatite (HA), which are usually used as internal layers of functionally graded materials to withstand heavy load. Optical microscopy (OM), X-ray diffractometry (XRD), and scanning electron microscopy (SEM) were used to analyze the microstructure of cold-pressed composites after sintering at 1,100vH. Quantitative analysis of volume fractions and mean particle volumes of the ceramic phase was adopted to further discuss the reaction between Ti and HA. CaO and Ti_xP_y were produced in the Ti-HA reaction. With the increase of HA volume fraction, the Ti-HA reaction could be divided into three stages including stable initiation, stimulating term and re-stabilization according to the quantitative characteristics of the ceramic phase.