From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Summary of various aluminium alloys used for bearing materials.
| Identifier | ExFiles\Box 115\5\ scan0082 | |
| Date | 1st March 1938 | |
| COPY...KES I.A.E. RESEARCH AND STANDARDISATION COMMITTEE Research Department, Great West Road, Brentford, Middx. No.8824. Class 278,57. March, 1938. Aluminium Bearing Materials. R.{Sir Henry Royce} Hinzman Zeit. f.{Mr Friese} Metallkde, May 1937, pp.158-162. The 'Borotal' aluminium alloys which are on the market vary in composition and hardness according to requirements. The alloys all contain about 0.1% graphite which aids lubrication when the oil film partially breaks down. The 'Borotal Z7' alloy contains 3-4% Cu, up to 2% Fe and 3% Pb and Zn, and has a hardness of 70 Brinell. This alloy has been used successfully for bearings of C.I. engines. For lighter loads, the 'D4' and 'D5' alloys can be used. Their composition is the same as that of 'Z7' alloy, except that they do not contain Zn and their hardness ranges from 55 to 62 Brinell. For small bearings, the 'Borotal FZ 17a' alloy, having a hardness of 40 Brinell can be used. This alloy has the same composition as the 'Z7' alloy except that Copper is omitted. Aluminium bearings which have been used successfully with hardened steel journals are the 'Alugir', containing 3% Cu. 0.8% Zn and 1 to 1.5% Ni, the Chromet containing 10% Si and the RR 56 alloy. The 'Quarzal' alloy, containing 5% Cu and 1.0% additions from the iron group as well as 0.5% other additions has also been used successfully both with plain and hardened journals. To ensure success with 'Quarzal', the bearings should be diamond-bored and the clearance correctly chosen to allow for the high coefficient of expansion. The silicon al loy 'KS 280' containing 21 to 22% Si, 1.2% Co, 1.5% Cu, 0.6% Mn, 1.5% Ni and 0.5% Mg has a structure similar to that of a white metal bearing. The hardness of 120 Brinell necessitates the use of a hardened and highly polished journal, a carefully designed bearing shell with correct bearing clearances and the use of clean oil. The wear of the 'KS 280' alloy is only about one-seventh that which occurs with lead bronze or tin bronze materials. The 'KS 13' alloy contains 6 to 8% Sb{Mr Bull/Mr Bannister} and has a hardness of 40 Brinell. This alloy extrudes easily and is, therefore, best used as thin bearing metal for composite bearings with shells of 'KS 280' or duralumin alloys. | ||