Research on the porous Ca/P bioactive ceramic coating prepared by laser cladding: The effect of polymethyl methacrylate pore-forming agent addition amount on coating formation

Abstract

Porous bioactive ceramic coatings play a significant role in promoting rapid osseointegration between titanium alloy artificial joint stems and host bone. However, fabricating such coatings remains challenging. In this work, the porous bioactive ceramic coating with a three-layered structure was prepared on medical-grade pure titanium via laser cladding. The coating structure consisted of a porous bioactive layer, a transition layer, and a Ti-locking layer in a top-to-bottom sequence. Hydroxyapatite (HA) served as the primary material for preparing the porous bioactive layer, while polymethyl methacrylate (PMMA) was incorporated as a pore-forming agent to create an interconnected porous structure within the coating. The study thoroughly investigated the effect of PMMA addition amount on the phase composition and bioactive substance content, as well as the internal pore diameter, morphology, and porosity within the bioactive layer. The formation mechanisms of the porous structure within the porous bioactive layer were further elucidated. The results showed that when PMMA addition amount was 15 wt%, the porous bioactive layer had a uniform distribution of micropores, forming a well-interconnected porous structure, and the coating formation quality was excellent. This research has important implications for achieving rapid osseointegration between artificial joint stems and host bones.