Technical Note 6 Heat Treating

Plot of corrosion potentials of pure aluminum and binary aluminum plus copper alloys, plus the two stoichiometric precipitates. The binary alloys were fully solution heat treated and quenched as rapidly as possible to retain the maximum amount of copper in solid solution. Note that the addition of copper raises the corrosion potential of pure aluminum by about 0.14 V. (Courtesy of Alcoa Technical Center, Marsha Egbert.)... 

In a 5-I. round-bottom flask fitted with a stopper holding a condenser set for downward distillation and a thermometer which will extend well into the liquid, are placed 4000 g. of technical formaldehyde (35-40 per cent sp. gr. 1.078 at 20°) and 2000 g. of technical ammonium chloride. The mixture is heated on the steam bath until no more distillate comes over and then over a flame until the temperature of the solution reaches 104°. The temperature is held at this point until no more distillate comes over (four to six hours). The distillate, which consists of methylal, methyl formate and water, may be treated as described in Note 3,... 

---