EFFECT OF MICROSTRUCTURAL FEATURES ON THE FRACTURE-TOUGHNESS OF A WELDED ALPHA-BETA TI-AL-MN ALLOY

The fracture toughness of weld fusion zones in a dilute, medium-streng th alpha-beta Ti-Al-Mn alloy has been studied in relation to their mic rostructures. Welding was performed over a range of energy inputs usin g different techniques. The weldments were subjected to three differen t annealing treatments. It has been shown that the fracture toughness of all weld metals is greater than that of the parent material. The da ta also reveal that there is a further improvement in fracture toughne ss on post-weld heat treatment. The results are discussed in terms of the structural changes occurring during welding and subsequent anneali ng. (C) 1997 Elsevier Science Ltd.