•Preparation of TiB2–Ni coating from agglomerated powder and clad powder•Loss of TiB2 in plasma spraying by particle rebounding and dissolution•Relationship between of the characteristic of TiB2–Ni feedstock and the coating microstructure as well as its performanceIn this work, TiB2–Ni cermet coating was deposited by atmospheric plasma spraying using two kinds of feedstock, namely agglomerated powder and clad powder. The microstructure and the phase composition of the powder, as well as the sprayed coating were analyzed. The microhardness (Hv) and the fracture toughness (KIC) of the coating were also evaluated. The results showed that the phenomenon of TiB2 particle's rebounding in deposition and the dissolution of TiB2 were closely related to the feedstocks' characteristic, e.g. TiB2 particle size, binder content and its morphology, which played an important role on the coating microstructure and its mechanical properties. The tribological performance of the coating was also assessed using a linear reciprocating friction tester with GCr15 counterpart. The coating deposited from agglomerated and sintered TiB2–40 wt.% Ni powder presented better tribological properties, i.e. low friction coefficient and wear rate.

Hydroxyapatite/ZrO2 graded coating was deposited onto Ti–6Al–4V substrate by atmospheric plasma spraying. The adhesive strength of the graded coating was tested and the bioactivity was evaluated in vitro by incubation test in the simulated body fluid (SBF). The results indicated that the graded coating has improved bonding strength and the crystallinity of hydroxyapatite can be improved using a post heat treatment. The bioactivity of the hydroxyapaptite/ZrO2 graded coating was also confirmed.