In order to understand the friction and wear properties of NiCr coatings with different Al

2

O

3

mass fraction

the NiCr coatings with Al

2

O

3

mass fraction of 10%

15% and 20% were prepared on the surface of valve steel by laser cladding technique. The microstructure

element composition

phase

hardness

friction coefficient and wear volume of different coatings were analyzed by scanning electron microscopy

energy spectrometer

X-ray diffractometer

microhardness tester and high temperature friction and wear testing machine

and the wear mechanism of different coatings was explored.The results show that the surface hardness of the three groups of coatings is obviously improved

and the average friction coefficient reaches 0.152

0.114 and 0.095

respectively.The coating surface with Al

2

O

3

mass fraction of 10% presents slight plastic deformation

obvious adhesive wear and local oxidation.The surface plastic deformation of the coating with Al

2

O

3

mass fraction of 20% is serious

accompanied by slight oxidation wear and microcrack.The coating with an Al

2

O

3

mass fraction of 15% has the minimum wear volume

with only slight adhesive wear and oxidation wear.