Casting Heat Treatments & Annealing

Casting Heat Treatments and AnnealingHeat 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

O: Annealed

T4Solution 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.

Contact us today with any questions you may have on your next non-ferrous casting project or check out our other value-add foundry services: