Thermal Stress Relief in 7050 Aluminum Forgings by Uphill Quenching
A novel deep cryogenic treatment is presented to relieve residual stresses in 7050 aluminum alloy parts, in which the parts are submerged in liquid nitrogen and uphill quenched in proprietary QCW-01 quenchant. The optimum parameters of uphill quenching process were concluded in an attempt to combine maximum stress relief with the required levels of mechanical properties. The experimental results show that this novel deep cryogenic treatment can relieve as much as roughly 71% of residual stresses, higher than the traditional treatment uphill quenched in boiling water. An application example is highlighted, in which this uphill quench treatment has resulted in lower levels of residual stresses and machining distortions for an aircraft bulkhead forging.
Sabine Denis, Takao Hanabusa, Bob Baoping He, Eric Mittemeijer, JunMa Nan, Ismail Cevdet Noyan, Berthold Scholtes, Keisuke Tanaka, KeWei Xu
Q.C. Wang et al., "Thermal Stress Relief in 7050 Aluminum Forgings by Uphill Quenching", Materials Science Forum, Vols. 490-491, pp. 97-101, 2005