Wear resistance of a protective coating of a nickel boride-nickel alloy

The investigations reported on in this paper show that the friction pair consisting of the coating of the nickel boride-nickel alloy and rubber is characterized by high endurance in the condition of sliding friction in a clay solution with an abrasive material. The wear resistance of the coating was compared with that of 40KhA and 20Kh13 steels (HRC /SUB r/ 52-55). The tests were conducted on the specimens in the form of the rotor of a screw drilling motor D85. The counterbody was represented by the specimens' having the profile of the stator of the same motor. The axis of the specimen was displaced in relation to the axis of the specimen of the starter by eccentricity equal to half the height of the tooth. Testing showed that the wear resistance of the experimental steel radial sliding supports hardened with the nickel boride-nickel protective alloy is twice as high as the resistance of the rubber-metallic sliding supports (in which the internal surface of the outer ring is rubber-coated and the internal ring is made of 40 KhA steel).