Three quenching mediums are oil (least hardness), water (medium hardness), or brine (most hardness) Hardening . Tempering . Annealing . Normalizing . Casehardening - Carburizing - Nitriding You will be defining each of these in Lab Project #1 Also refer to "Heat Treat Processes" handout Commercially pure aluminum is a white lustrous metal, which stands second in the scale of malleability, sixth in ductility, and ranks high in its resistance to corrosion. The system is broken into three distinct groups: 1xxx group, 2xxx through 8xxx group, and 9xxx group (which is currently unused). - The first digit of a designation identifies the major alloy element. - The second digit indicates specific alloy modifications. - The last two of the four digits in the designation identify the different alloys in the group. (with the exception of the 1xxx) Aluminum Alloys: - Solution Heat Treatment - Precipitation Heat Treatment . Also known as "Artificial Aging Reheating a heat treated alloy metal with a welding torch can significantly alter the metal's properties in the reheated area. . It is preferred to re-heat treat the entire material, using the method that will achieve the desired properties. When a mechanical force is repeatedly applied to most metals at room temperature, such as rolling, hammering, or bending, the metals becomes cold worked, strain or work hardened