The　spark　plasma　sintering　(SPS)　behavior　of　binder-free　WC　was　investigated　by　a　series　of　experiments.　The　appropriate　contents　of　carbon　addition　to　form　dominant　WC　phase　were　determined　corresponding　to　different　sintering　parameters.　By　optimizing　the　processing　parameters,　with　0.1　wt%　carbon　addition　and　sintered　at　1460　degrees　C,　the　WC　cemented　carbides　of　high　density　and　a　fine　microstructure　with　grain　sizes　less　than　350　nm　were　obtained.　By　means　of　TEM　and　high-resolution　transmission　electron　microscope　(HRTEM)　observations,　the　clean　WC　grain　boundaries　were　found,　and　the　orientation　relationship　between　neighbouring　WC　grains　was　studied.　The　advantages,　as　well　as　the　mechanisms　of　SPS　sintering　binder-free　WC,　were　also　discussed.　(C)　2008　Elsevier　B.V.　All　rights　reserved.