Effect of Hot Treatment on Mechanical Properties and Microstructure of a New Type Al-Cu-Li Alloy

Basal investigation of a new type Al-Cu-Li alloy was carried out.The peak-aging of the new type Al-Cu-Li alloy was determined through tensile tests and the Transmission Electron Microscopy(TEM) was used to investigate the microstructure of the experimental alloy.Precipitates δ′,T1,σ,θ′,θ″ were found in the alloy.The mechanical properties changing with different kinds and amount of precipitates were analyzed.The work showed that the compound effect of precipitation δ′ and θ′ attribute to the matrix strengthening and that the strengthening effect of precipitation σ was more effective than precipitation θ′.Precipitation θ″ kept decreasing with aging process and disappeared at last.The qualitative relationship of mechanical properties and microstructure was established.