Die shape compensation in hot forging of titanium aerofoil sections

Dimensional accuracy is among the most important criteria in hot forging of titanium alloy into aerofoils for aeroengine applications. This paper presents a study of dimensional errors of hot forged aerofoil sections in an entire forging cycle using finite element (FE) simulation. It was found that the die-elasticity and thermal distortion had an important effect on thickness error and profile deviation of the aerofoil sections. By modifying die profiles using two weighting factors representing aerofoil errors due to the die elastic deflections in forging and aerofoil thermal distortion during cooling, a significant reduction of both the aerofoil thickness and profile errors was obtained.