Method of producing accurately scaled, well-defined surfaces of work pieces from carbonaceous cast iron with tribologic properties
AssigneeAudi AG
InventorsKlaus Heck, Horst Lindner
Life of this patent
Estimating the term…
Abstract
The invention relates to a process for producing accurately scaled, well-defined surfaces of workpieces made from carbonaceous cast iron and having tribologic properties, more particularly of cylinders or internal combustion engines, said surfaces being subjected to at least two operating cycles consisting of an electrochemical and a subsequent mechanical removal. To obtain a constant surface quality, at least the last operating cycle is carried out in a specified ratio between the electrochemical and the mechanical removal and this is a fixed removal ratio. Preferably, a metal bearing plateau percentage of 40 to 65% of the surface is produced with the last operating cycle.
Claims4
Method of producing accurately scaled, well-defined surfaces of workpieces made from carbonaceous cast iron and having tribologic properties, comprising subjecting said surfaces to at least two operating cycles, starting with a first cycle and concluding with a last cycle, each cycle including an electrochemical and a subsequent mechanical removal in order to create surfaces with a proportion of metallically bearing plateaus which are partially clad with graphite and mixed crystals and with open areas covered with graphite flakes and having a modest micro roughness, carrying out at least the last operating cycle in a specified ratio between electrochemical and mechanical removal to produce in the last operating cycle a metallically bearing plateau proportion of 40% to 65% of the surface.
Dependencies are inferred from the claim text.