Vacuum Heat Treating in Aluminum
Advances in vacuum furnace gas quenching processing continue to expand the materials that benefit from this technology. Fabricators of aluminum are discovering the benefits of minimized distortion and clean parts that vacuum processing offers. Solar Atmospheres, Hermitage, PA, recently solution aged 6061 aluminum from 0 to a T6 condition. This task was accomplished because of the plant's 12 foot furnace and its Advanced Quenching capability.
Airwolf Helicopters, Middlefield, OH manufactures aluminum booms for crop dusting. The twelve foot booms included smaller tubing, 1 3/8" dia. x .058 wall thickness, and larger tubing that ranged from 1 5/8" to 2 1/2 " dia. x .058 wall thickness. Because of the thin wall and long length, water quenching would cause extreme distortion and contamination. Solar's large furnaces and Advanced Quenching capability were the best alternative to attain material specifications while minimizing distortion.
To put the aluminum in solution, Solar uses a nitrogen partial pressure atmosphere in the vacuum furnace and gradually heat treats the aluminum up to 985° F. The material is held at this temperature and then a 2 bar, helium quench is performed. This brought the material to a T4 condition. While still in the furnace, age hardening is done in a nitrogen partial pressure environment. The aluminum is heated up to 350° F and held at that temperature for eight hours. The tubing is quenched in nitrogen. Required properties of the TE condition is an ultimate tensile strength of 42 KSI with yield strength of 35 KSI. Actual results attained were UTS of 42.1 KSI and yield strength of 38.6 KSI
A significant factor that contributed to the success of this job was the thin wall tubing. Solar's Advanced Quenching is continually improving and becoming more effective in cooling to achieve material specifications while minimizing distortion for oil and water quench materials. For comments or questions please contact Bob Lacock, rdl@solaratm.com
Bob Lacock
Solar Atmospheres
Marketing Manager
800.347.3236 x 213
rdl@solaratm.com
www.solaratm.com
