A study using transmission and scanning electron microscopy was made of the evolution of the microstructure of electroless plated Cu on activated amorphous substrates and on singlecrystal Cu grains. On amorphous substrates activated in a PdClj-SnClj colloidal solution, Sn atoms dissolved into the plating solution concurrently with Cu deposition on the substrate during the initial stage of deposition. The very small face-centered-cubic grains of Cu-Pd solid solution agglomerated into much larger particles and later coalesced into spherical grains. As the grains grew, they developed crystallographic facets, impinged upon one another, and finally covered the entire substrate. Grains of energetically favorable crystallographic orientation selectively developed into the columnar structure. These coiumnar grains contained subgrains, dislocations, and twins. Remarkably different structures were observed for the Cu grown on large single-crystal grains. In this case epitaxial growth dominated the plating process. Low-surface-energy (111) Cu planes were frequently observed on plated Cu surfaces. Growth rates were a function of substrate orientation. "

In order to obtain the apatite implants which can meet the requirements for both bonding strength and bioactivity, the FHA(Ca10(PO4)6OH2−xFx(x = 0 ~ 2)) gradient coating was prepared by electrophoretic deposition on the surface of titanium alloy (Ti–6Al–4V). The effects of fluorine substitution and gradient structure on the morphology, bonding strength, and bioactivity of the coating were investigated. The gradient coating has the dense inner layer and porous outer layer that were deposited by controlling the suspension concentration and the preparation process. Through controlling of the fluorine substitution gradient, the thermal expansion coefficient gradually changed to improve the bonding strength more than 30 Mpa. The inner layer with high fluorine content can improve the thermal stability of the coating and bonding strength between the coating and the substrate, while the proper content of fluorine in the outer layer improves the bioactivity of the gradient coating.