THERMISCHES BESCHICHTUNGSVERFAHREN, INSBESONDERE FÜR GLEITLAGER

摘要

When plain bearings are producing by thermal coating the coating flame also results in oxidation of a part of the coating material. To reduce this oxide formation and especially to lower the formation of oxide clusters the burner flame has a gas stream next to it which is oxygen-reduced in relation to air. Preferably only nitrogen (>/=99%) is used as cooling gas for the burner (51). The method provided for in the invention is preferably used to provide a connecting-rod eye with a sliding layer. The large connecting-rod eye (3) is subjected to pre-spindle trimming, cracking and further spindle trimming to the coating tolerance, sandblasted and microporously plasma-coated with an aluminium bronze. At the start of plasma spraying the plasma layer is deposited at a high temperature, which results in good adhesion of the plasma layer to the material of the connecting-rod eye and low porosity of the plasma layer. To prevent annealing of the material of the connecting-rod eye the deposit temperature of the plasma layer is lowered for that area which is removed by subsequent working of said plasma layer. After plasma coating the connecting-rod eye is opened by removing the bearing cap (9), which ruptures the plasma layer (16). The cap (9) is then screwed back on and the actual sliding layer created by fine spindle trimming. To improve the oil retention volume the plasma layer (16) has an annular groove (32). The invention is used in internal combustion engines.