Abstract: The method of electrical discharge coating with TiC4 ceramic layer in ordinary electrical discharge machining (EDM) tool is studied. TiC4 ceramic layer is deposited on 45 carbon steel substrate by EDM technique. TiC4 ceramic coatings with different contents of lanthanum are fabricated on a 45 carbon steel substrate. The clad coatings are examined and tested for microstructural features, chemical compositions, phase struc-ture, friction and wear properties by scanning electron micro-scope (SEM), X-ray diffraction (XRD) analysis, hardness tester, block-on-ring friction and wear tester separately. Experimental results show the TiC4 ceramic coating can be deposited on sur-face of carbon steel substrate, and the electrode mix into rare earth lanthanum oxide helps to enhance the density of coating, and the coating’s wear resistance can be increased, when the content of lanthanum oxide increases to 0.5%, the clad coating shows the best anti-wear ability, wear resistance can be in-creased by three times, and the wear coefficient can be de-creased by 10%. When the clad coating’s surface doped with excessive La2O3, it is found that there are many minute holes and long flaws cross specimen’s surface, and the clad coating’s surface roughness increases, wear resistance properties of the cladding layer declines quickly.

Key words: Rare earths, Ceramic coating Surface modification, Electrodeposition technology