Effect of Heat Treatment on the Mechanical Properties of Aluminum Alloy 2219 and Its Welded Joints at Cryogenic and Elevated Temperatures

The effect of heat treatment on mechanical properties of welded joints of aluminum alloy 2219 for different types of heat treatment (T62, T81, and T851), types of rolled products (plate with thickness of 40 mm and sheet with thickness of 5 mm) depending on the direction of the weld. In a wide interval of operating temperatures the temperature limits of strength and fluidity, relative elongation after rupture and modulus of elasticity were obtained. It is shown that heat treatment to the thermal state T62 – in comparison with T81 and T851 – is the most effective for strength of material. In this case there is a rather small decrease of strength characteristics with increasing temperature up to 200°C. It is noted that the alloy under study is characterized by significant anisotropy of mechanical properties in the entire temperature range, and the location of the welded seam of the sheet material along the rolling direction relative to the direction across the rolling allows to increase to 5% of the ultimate strength.