Aging System 7B04 Aluminum Alloy Performance

Aiming at the state-of-the-art of 7B04 aluminium alloy ,this paper has studied the effect of heat treatment on organization and performance.The influence of ageing technology on normal performance and fracture toughness along with stress corrosion is mostly investigated. The three-point bending and V-shaping test methods are used to get the fracture toughness.Microstructure and fractography are also analized through stereoscan and transmitted photograph. Reasonable production technology is got by synthetizing these tests and analyzing mechanism.Results of the study show that:1. In the course of two-stage ageing,strengthness and hardness fall down but fracture toughness and stress corossion resistance increase with the rising of the second stage aging temperature and prolonging of the time.Moreover the influence of temperature on it is greater than time.2. As the continuous chain distribution in grain boundary of T6 state,fracture toughness and stress crossion resistance are low.The strengthness is largely costed to get preferable fracture toughness and stress crossion resistance in T73 and T76 state.Regression and Re-aging(RRA) can get super strengthness and preferable stress corrosion resistanee,but its fracure toughness is low.3. The self-defining overageing technology 115℃ X7h+185℃X 13h assures that 7B04 aluminium alloy can get preferable combination property on the premise of proper strengthness.And it can be used to produce.