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).
Hall's Metal Bearings, discussing adhesion, expansion rates, and yield points of bearing materials.
| Identifier | ExFiles\Box 114\2\ scan0239 | |
| Date | 28th November 1935 | |
| L.A. Smith X1020 Hs.{Lord Ernest Hives - Chair} from E.{Mr Elliott - Chief Engineer} c. Sg.{Arthur F. Sidgreaves - MD} Wor.{Arthur Wormald - General Works Manager}By.H1.E/Bn.{W.O. Bentley / Mr Barrington} E/JNR.{Charles L. Jenner} E.5/HP.28.11.35. Hall's Metal Bearings. Referring to report Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer}18/KW.25.11.35, an examination of these results conveys to me the impression that there may be some other factor to consider than getting the initial adhesion right in manufacture. I refer to the quarrelling which will take place between the bearing metal and the steel liner at working temperatures due to the bearing metal having twice the expansion rate of the steel. In the case of white metal where the expansion rate is 1.8 times that of the steel the occasion appears to be met in a remarkable way by the softening of the white metal, allowing it to yield without flowing until abnormal temperatures are reached. Where, however, the liner material still remains strong this may result in pulling it away from the steel backing, in other words, it may be that we have got to strike a balance between the yield point on the bearing metal and the adhesion. The following table shows some of the figures involved:- Bearing Metal. Brinell Cold. Brinell at 150°C. Yield Point at 150°C. Solid bearing material containing 7% tin as used on the testing machine giving initial results with this bearing alloy. 51 48 9 tons. Liner material containing 17% of tin used on tests reported in Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer}18/KW. 25.11.35. 26 21 3¼ tons. | ||