Over the last decade, there is an effort to reduce the vehicle body weight by the use of lightweight high strength aluminum (Al) alloys.

The 7xxx series of aluminium alloys provides a high strength to weight ratio compared to other classes of aluminium alloys for aerospace structures and allows achieving the two important goals: fuel consumption and service life.

Presently AA 7075, AA 7050, AA 7055, AA 7010, AA 7085 are some of the typical aluminium alloys used in aerospace industries. AA 7010 was considered as an important milestone in aluminium alloy development as it replaced classical AA 7075 in large die forging application whilst it encountered several environmentally assisted cracking (EAC) failures.

However, the fusion welding of 7xxx series of aluminium alloys are not consider by the aerospace industry until the past decade. Particularly, solidification cracking within the fusion zone, liquation cracking at the boundary between the fusion zone and the HAZ and poor corrosion performance has been observed in such conventional fusion welding.

Unfortunately, commercially available Al-filler rods have not been compatible to reduce solidification cracking; coarse grains in fusion zone specifically for AA7010 aluminium alloy and currently provide insufficient strength for many applications.

It will be necessary to develop modifying filler rod by adding ceramic particle (TiB2) and weld procedures which enable joints to be completed having properties comparable to those of the parent metal. Finally, the microstructure of the joints has been correlated with the measured mechanical properties.

This article is shared by A K Pramanick and D Gonda of National Institute of Advanced Manufacturing Technology.