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).
Micro-examination report on 'Brico' brake liners made from 'Brimal' cast iron.
| Identifier | ExFiles\Box 141\1\ scan0078 | |
| Date | 19th November 1935 | |
| Copy for Ferodo's Micro-Examination Report. M1080. To Hs{Lord Ernest Hives - Chair}/Gry.{Shadwell Grylls} HL2/AG.19.11.35. Laboratory. c.c. E.{Mr Elliott - Chief Engineer} c.c. B.V. MARTINDALE Brake Liners. The "Brico" liner made in "Brimal" austenitic cast iron, and intended for use in an aluminium drum, has been examined, as requested. Three specimens, A, B, C were taken from one edge of the liner at equidistant points in the circumference, and three more, A1, B1, and C1 were cut from the other edge at points opposite to A, B, and C respectively. The concave surface of each specimen, representing the inner surface of the liner, was filed flat and polished for micro-examination. The graphite distribution is illustrated by photomicrographs Nos. A1,312 to A1,317, X100. It will be seen that the graphite form is compact and small. Specimens B1 and C1 showed a smaller quantity of graphite than the other four specimens. Compared with Lake and Elliot's "Millenite" drums, the graphite of the "Brimal" centrifugally cast liner is on the average rather smaller. Photomicrographs Nos. A1,319 and A1,320, X100 show respectively, the graphite in Lake and Elliot's brake drum specimens Nos. 64 and 66 which you handed to us some time ago. The hardness of these was 217-241 Brinell and 269-285 Brinell respectively. Photomicrograph No. A759, X100 - see Report L2346-1/3/32 shows the graphite in a "Millenite" drum which was considered on test to be satisfactory. This had a Brinell of 255-260. Photomicrograph No. A1,156, X100 - see Report L3,115 - 19.10.34 shows the coarser graphite in a drum which was reported to be worn after 10,000 miles. Brinell 210-228. Apart from the graphite, the structure of "Brimal" austenitic cast iron - See A1,318, X150, of the etched specimen "B", is of course quite different from that of "Millenite", which has a pearlite matrix, (See A1,321 and A1,322). contd. | ||