Wear and sliding friction properties of a number of nickel alloys operating against hardened SAE 52100 steel were studied. The alloys were cast beryllium nickel, heat-treated beryllium nickel, cast Inconel, Nimonic 80, Inconel X, Refractalloy 26, and Discaloy. Some of the allows studied may be useful as material for cages of rolling-contact bearings that operate at high speeds with temperatures above 600 degrees F in projected aircraft turbine engines or for bearings that operate in corrosive mediums. Desirable operating properties and the absence of extreme mass welding of all the materials could be associated with the development of the sliding surfaces of a naturally formed film of nickel oxide. On the basis of wear and friction properties, cast Inconel performed very well in these experiments and compares favorably with nodular iron. Nimonic 80 also showed promise as a possible cage material.

As predicted by friction theory, experiments showed that friction and surface damage of metals can be reduced by solid surface films. The ability of materials to form surface films that prevent welding was a very important factor in wear studies of dry and boundary lubricated surfaces. Films of graphitic carbon on cast irons, NiO on nickel alloys, and FeO and Fe3O4 on ferrous materials were found to be beneficial. Abrasive films such as Fe2O3 on MoO3 were definitely detrimental. It appears that the importance of oxide films to friction and wear processes has not been fully appreciated.

An experimental investigation to determine the relative merits of bronze and nodular iron as cage materials for cylindrical-roller bearings was conducted using four identical 75-millimeter-bore outer-race-riding cage-type cylindrical-roller bearings (tow with bronze cages and two with nodular iron cages). The test bearings were operated over a range of DN values (product of bearing bore in mm and shaft speed in rpm) from 300,00 to 2,100,000, oil flows from 2 to 8 pounds per minute, and loads from 7 to 1613 pounds.

An investigation of four experimental and two conventional 75-millimeter-bore (size 215) cylindrical-roller bearings was conducted over a range of DN values (product of bearing bore in mm and shaft speed in rpm) from 300,000 to 2,300,000, radial loads from 7 to 1613 pounds, and oil flows from 2 to 8 pounds per minute with a single-jet circulatory oil feed. The four experimental bearings were equipped with outer-race-riding cages and inner-race-guided rollers. One conventional bearing was equipped with an outer-race-riding cage and outer-race-guided rollers, while the second conventional bearings was equipped with an inner-race-riding cage and inner-race-guided rollers. Each of the six test bearings was equipped with a different design cage made of nodular iron.