White Metal Babbitt for Rolling Mill Bushing

Abstract

A tin based white metal alloy consisting essentially by weight of approximately 5.0%-0-9.0% antimony, approximately 3.0%-8.0% copper, approximately 0.1%-0.7% cobalt, and the balance tin.

Description

CROSS REFERENCE TO RELATED APPLICATION[0001]This application claims benefit, under 35 U.S.C. §119(e), of U.S. Provisional Application Ser. No. 61 / 541,395, filed 30 Sep. 2011, the entire contents and substance of which is hereby incorporated by reference.BACKGROUND[0002]1. Field[0003]Embodiments and aspects of the present invention relate to tin based white metal alloys useful in various industrial applications, including the bushings of rolling mill oil film bearings.[0004]2. Description of Related Art[0005]The most prominent white metal alloy used in oil film bearings in the rolling mill field is described in ASTM B23 #2, (referred to here as ASTM #2) and is comprised primarily of tin, with antimony and copper, as alloying elements. ASTM #2 is well understood and is readily deposited onto bushing shells via centrifugal casting, spray deposition, or welding. Unfortunately, ASTM #2 has relatively low fatigue resistance, which limits load capacity of bearings made with this material.[...

AI Technical Summary

Benefits of technology

This patent is about a new kind of metal alloy that is safe and doesn't contain any harmful substances like cadmium. It's made up of tin, which is a safe element to have in large amounts in humans. The benefit of this new alloy is that it's safer and more stable than other similar alloys, which can be toxic and carcinogenic.

Problems solved by technology

Unfortunately, ASTM #2 has relatively low fatigue resistance, which limits load capacity of bearings made with this material.

These alloys can be cast and welded, but they contain Nickel, which is a heavy metal that is undesirable for environmental reasons.

But due to the brittleness of the zinc component, this alloy cannot be readily drawn into wire for use in spray and welding applications.

Cadmium is a known carcinogen that has been banned from most workplaces and thus is undesirable.

The inclusion of chrome is impractical as it is not readily soluble under normal alloying conditions.

Such coatings lack the toughness required for heavily loaded oil film bearing applications, and the disclosed use of cobalt at elevated percentage levels would inhibit the flow characteristics necessary in a casting or welding process.

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