Chemical analysis procedure for determining the composition of a bearing alloy.
| Identifier | ExFiles\Box 115\5\ scan0172 | |
| Date | 16th November 1938 guessed | |
| 1020a~ 5. ANALYSIS OF BEARING ALLOY. Determination of Tin. Dissolve 1 gm. of drillings in 100 cc. of 80% hydrochloric acid, in an atmosphere of carbon dioxide. Ensure that soln. of aluminium and tin is complete and then cool to below 20°C Titrate with N/20 iodine soln. When oxidation of the tin is complete, one drop of soln. in excess will give a yellow colour. Determination of Manganese. Dissolve ½ gm. of drillings in 25 cc. of 10% caustic soda. Acidify with dilute sulphuric acid and add 5 cc. of nitric acid. When soln. is complete add 10 cc. of 1% Silver Nitrate soln., make up to 100 cc. and bring to the boil. Add 1 gm. of Ammonium Persulphate and boil for 1 min. Cool and titrate with standard sodium arsenite. Determination of Silicon. Dissolve 2 gm. of the alloy in aqua regia evaporate to fuming with sulphuric acid, dilute with 10% hydrochloric acid and boil till all in soln. except silica. Filter and wash with 5% hydrochloric acid soln., ignite and weigh. Determination of Iron. Colorimetric with ammonium thiocyanate as for RR.50 using a corresponding blank. Determination of Magnesium. Dissolve 2 gm. of alloy in 10% caustic soda. Dilute, allow to settle and filter. Dissolve residue in nitric acid, evaporate with sulphuric (10 cc.), dilute, ppt. tin as sulphide and filter. Take filtrate, boil off hydrogen sulphide oxidise, add 1 gm. of tartaric acid, and make alkaline with ammonia. The solution should be clear. Add 10% 20 cc. ammonium phosphate soln. and excess ammonia to ppt. magnesium as phosphate. Filter off, wash, ignite and weigh. Some manganese phosphate is co-pptd. and is determined in the ignited ppt. after dissolving in sulphuric acid, as above. (See determination of manganese). Determination of Nickel. Dissolve 2 gm. of the alloy in hydrochloric acid, oxidise with nitric acid, add 10 gm. of tartaric acid, dilute to at least 100 cc. and make alkaline with ammonia. Ppt. nickel with dimethyl-glyoxime, filter off, wash, and dissolve in dilute hydrochloric acid. Boil to destroy dimethyl-glyoxime, make just alkaline with ammonia and after cooling titrate with potassium cyanide using silver nitrate and potassium iodide as indicator. Determination of Copper. Dissolve 2 gm. of the alloy in 10% Caustic Soda. Dilute, allow to settle and filter. Dissolve residue in nitric acid, evaporate with sulphuric acid (10 cc. of 50%), dilute and ppt. tin and copper as sulphide. Filter off and ignite the sulphides. Dissolve oxides in strong nitric acid and estimate as usual with dilute sodium thiosulphate and potassium iodide. | ||
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).