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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
structure, friction and wear properties by scanning electron
microscope (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
surface 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 increased by three times,
and the wear coefficient can be decreased 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: Electrodeposition technology Ceramic coating Surface modification Rare earths
CLC No: TH117.1
国家自然科学基金资助项目(50675125). Received 20060704,
received in revised form20061230
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