Wear and corrosion resistant aluminium cylinder - operating with a piston provided on the internal surface with an aluminium oxide or nickel coating

摘要

A cylinder made of Al, for a servomotor with a piston and exposed to a hydraulic fluid, is given improved wear and corrosion resistance by forming a layer on the internal surface of the cylinder. This layer is in intimate contact with the surface, =5 mu thick and in gliding contact with the piston. It may be made of Al oxide by anodic oxidn., or is a Ni layer produced electroless and contg. a phosphorus cpd.