Wear-resistant material, puffer cylinder, and puffer-type gas circuit breaker

A puffer cylinder formed of being linked with a movable-side arc-contactor which is arranged capable of contacting with and separating from a stationary-side arc-contactor, fitted with a piston inside thereof, and the piston slidably moving against the inner-wall surface of the puffer cylinder in order for the piston to suck in, or spurt an arc-extinguishable gas, the puffer cylinder comprising:

• a base material of pure aluminum or an aluminum alloy which has a plurality of depressions randomly disposed on an inner-wall surface thereof;
• and
• a hydrated oxide coat of aluminum formed on the inner-wall surface of the base material,
• wherein each of the depressions has a depth of 1 μm or more and a diameter between 5 to 30 μm, and
• wherein the hydrated oxide coat includes a plurality of protections each having a length not more than 1 μm, and the hydrated oxide coat has a thickness of 1 μm to 3 μm.