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).
Metallurgical report on the effects of adding Antimony and Bismuth to remelted aluminum-copper alloys.
| Identifier | ExFiles\Box 76\3\ scan0009 | |
| Date | 25th June 1919 guessed | |
| Report L 533 contd No 1 alloy was remelted, with an addition of 1.0% Aluminum & 1.0% Antimony it gave tensile strength on the average 12% higher than alloy remelted without additions. From this and previous tests it appears that copper 10.5%? gives the best results. Under founding Antimony 1.5% conditions about 2.2% Antimony must be added to get 1.5% in cast metal. Antimony acts (i) as a deoxidiser (ii) seems to stop evolution of gas at the moment of solidific- -ation (iii) somewhat reduces size of grain & cellularity of cast metal (specially noticeable in high Copper-Alum alloys) The curve indicates that Antimony reduces the lower recalescence point on cooling with copper only about 8.0% this becomes ill defined at 530°C (curve (i)) though this change point is 10 to 20°C lower in the case of the antimony it is considerably less & it appears that the change starts earlier i.e. soon after solidification & finishes with a final marked retardation at about 528°C. Miralite (iii) also has a reduced 2nd recalescence as shown on curve. Another alloy giving high tensile strength at ordinary temperature is one containing - Copper 9% Bismuth 1.5% Aluminum 89.0% The price etc of Bismuth being looked up. Enclos. one half test bar (to show non porous nature with up to 12.5% high copper) two microphotographs | ||