Copper tungsten material (CuW) is the most widely used electrical contact material for high voltage circuit breakers. The ablative properties of contacts directly affect the service life of high voltage circuit breakers and the safety of power grid. In this paper

Gr (Graphene) CuW contacts with different W content (70%

75%

80%

85%) are installed in a 40.5 kV circuit breaker to perform 20 arc ablation experiments under 23 kA experimental current. The changes of mass

length

contact resistance

surface macroscopic and section microscopic ablative morphology of GrCuW contacts with different W content are studied. The results show that when the content of W in GrCuW is 70%~80%

the ablative surface of arc contact tends to be flat

the contact resistance decreases

and the ablative resistance improves. The 80% W and 20% GrCu in GrCuW80 balance the hardness

toughness

and electrical conductivity of the contacts

giving the contacts superior arc ablation resistance. When the content of W is higher than 80%

the remelted W layer on the contact surface thickens and the ablative surface flakes off

which increases the contact resistance increases and decreases the arc ablative resistance of the contact. The optimization of the Cu to W ratio in GrCuW contact material is of great significance for CuW contact product development.