GB550485A - Improvements in or relating to hardened lead alloys, particularly adapted for use in bearings - Google Patents

Abstract

550,485. Alloys. STEVENS, A. H., (National Lead Co.). July 1, 1941, No. 8278. [A Specification was laid open to inspection under Sect. 91 of the Acts, Jan. 26, 1942.] [Class 82 (i)] A hardened lead alloy, particularly adapted for use in bearings, contains as a primary hardener 0.05-2.0 per cent. of calcium as inhibtor for oil corrosion 2.2-10.0 of tin, in the absence of cadmium and the balance lead with its usual impurities. The alloy may also contain as an auxiliary hardener 0.1-1.0, preferably 0.25. of mercury, as an anti-drossing agent 0.02.-0.15, preferably 0.05, of aluminium and also as auxiliary hardeners one or more selected from the group consisting of 0.02-0.1 of barium, 0.02- 0.5 of strontium, 0.05-1.0 of copper, 0.5-2.0 of silver and 0.05-0.5 of manganese. The alloy - is produced by melting the lead and heating at 1500‹F. under a covering of calcium chloride or other suitable flux, the aluminum introduced preferably as an alloy containing 50 per cent. of tin and the calcium in metallic form or in form of a calcium lead alloy containing 5 per cent. of calcium. If any of the auxiliary hardeners, silver, barium, strontium copper or manganese are employed they are introduced at this stage either in the form of pure metal or a tin or other alloy. The melt is then allowed to cool to 700‹F. and the flux covering skimmed off or the bath is allowed to solidify and remelted to about 700‹F. The tin is then added and the mercury, if the latter is to be included. Specification 525,375 is referred to. Reference has been directed by the Comptroller to Specification 433,653.