A BIMETALLIC STRIP FOR A SLIDING BEARING AND PROCESS FOR PRODUCING SAID BIMETALLIC STRIP

摘要

A bimetallic strip for a sliding bearing and process for producing said bimetallic strip, the latter being of the type comprising a sliding strip (1), which is made of aluminium alloy and which is adhered to a supporting strip (2), which is usually made of steel and which is optionally coated with a nickel coating interlayer (3). The process comprises the following steps) a- casting by the quick solidification process (roll cast) an alloy comprising from 3 to 30 % of tin, from 1 to 6 % of silicon and the remaining being of aluminium and accidental impurities, by pouring the cast alloy between two cold rolling cylinders, in order to obtain at least 95 % of the silicon particles smaller than 3.5 microns and an aluminum grain average size of about 6 microns; b) annealing the aluminium alloy sliding strip (1) in a heater at a temperature range from 200 to 500 DEG C; c) setting, optionally, the thickness of the sliding strip (1), through cold rolling passes, followed by respective annealings, as defined in the previous step; d) hot rolling (cladding) together the sliding strip (1) and the steel supporting strip (2), in order to form the bimetallic strip; e) heat treating the bimetallic strip between 200 and 380 DEG C, so as to obtain a metallurgical bonding between the strips; f) subjecting the metallic strip to a solubilizing process of the intermetallic compounds of the aluminum alloy, by sudden heating at 380-500 DEG C, followed by sudden cooling; and g) subjecting the bimetallic strip to an artificial precipitation treatment in a heater, at a temperture from 150 to 250 DEG C.