Patent ID: 6531089
Filing Date: 2003-03-11
Classification: B22F,C22C,C22F

Abstract:
A method of manufacturing cylinder liners and hydraulic or pneumatic working cylinders comprising the steps of:preparing an aluminum alloy consisting of a readily hot-deformable wrought aluminum alloy matrix of the type Al Mg Si Cu with a composition out of which no silicon primary crystals can crystallize, with a finely dispersed wear-resistance-increasing addition of at least one of uniformly distributed silicon particles and particles of a hypereutectic aluminum/silicon alloy, the individual particles of the hypereutectic aluminum silicon alloy having high silicon contents and the addition is at most 12% by weight silicon of the total silicon content of the aluminum alloy in the form of silicon particles and/or of silicon primary crystals in the particles of the hypereutectic aluminum/silicon alloy, preventing at least part of the silicon particles and/or primary crystals in the particles of the hypereutectic aluminum/silicon alloy from going into solution in the aluminum alloy matrix, preparing a billet from the alloy, hot deforming the billet by hot flow pressing into the cylinder liner or hydraulic or pneumatic working cylinder close to their final dimensions, wherein, the hot deforming step is controlled in such a way that the aluminum alloy which is processed into the cylinder liner or hydraulic or pneumatic working cylinder, after hot deformation and a subsequent optional heat treatment step, has a minimum content of silicon particles and/or silicon primary crystals which have not dissolved and have not separated out from the matrix alloy in the particles of the hypereutectic aluminum/silicon alloy relative to the total quantity of at least 5% by weight.