Effect of milling conditions on the properties of HA/Ti feedstock powders and plasma-sprayed coatings

• HA/Ti composite powders for plasma spray were prepared by ball milling.
• Milling time and rotational rates influenced the powders and coatings significantly.
• Increasing milling time and rotational rates caused changes in microstructure of coatings.
• Mechanical properties of coatings were dependent on milling conditions of feedstock.
• Apatite formed on the coatings after immersion in SBF for a certain time.

Various hydroxyapatite/titanium (HA/Ti) powders were prepared by ball milling using different milling times and rotational rates. The corresponding coatings were fabricated by air plasma spraying. The influence of milled powders on the microstructure and mechanical properties of plasma sprayed composite coatings was studied. The results showed the compositions of the plasma-sprayed coatings which were remarkably different from those of the initial powders. Increasing milling time and rotational rates reduced the porosity of the final coatings, thus improving their mechanical behavior. Apatite was formed on all the composite coatings after immersion in SBF for a certain time.