Heat treating a casting serves the purpose of improving or altering the physical properties of an as-cast part. There are various forms of heat treatment, but most involve heating the casting in an oven to a specific temperature range for a designated period of time then “quenching” the part (submerging in water or oil) immediately afterwards. Annealing is a form of heat treatment performed specifically on bronze alloys.
Benefits of Heat Treating a Casting
Heat treating a casting can be carried out in a number of different ways to achieve different results. Depending on the process used, heat treating can yield:
- Improved strength/hardness
- Improved machinability
- Improved dimensional stability
- Improved corrosion resistance
Patriot heat treats a variety of aluminum alloys. The most common alloys we heat treat are 356, A356, and 357. These are heat treated to a T5, T6, or T7 condition. These are made for the automotive, medical, military, oil & gas, communications, and electronics industries.
Patriot Foundry’s Heat Treatment and Annealing Services
Heat Treatment Types
F: As cast
T4: Solution heat treated and naturally aged to a stable condition
T5: Cooled from an elevated temperature shaping process and then artificially aged
T6: Solution heat treated and then artificially aged
T7: Solution heat treated and over-aged
Heat Treatment Definitions
Annealing: Heating castings to increase ductility, which also tends to decrease strength.
Solution Heat Treat: Heating castings to a suitably elevated temperature and holding at that temperature long enough to allow elements to enter into a solid solution and then cooling rapidly to maintain that solid solution.
Aging: Precipitation of solute atoms at room temperature (natural age) or elevated temperatures (artificial age).
Over-age: Additional aging to improve dimensional stability.
While heat treatment and annealing can improve certain qualities of a cast metal, it will add to overall production cost. Let the experts at Patriot Foundry help you decide on whether or not a heat treatment service will be of significant benefit to your application.