Evaluation of strength loss in heat affected zone of 6061-T6 aluminum alloy welded joints and its improvement by local post weld-heat treatment
Bombardier Transport (BT) is one of world major companies in the transport industry. The application of aluminum in the structure of transport vehicles (cars, trains, ships, etc.) is continuously increasing mainly due to the benefits in weight saving. Therefore BT is also working extensively in implementing the use of aluminum alloys in its products. Welding is one of the major manufacturing techniques used in the structure of transport vehicles. One of the common welding problems in aluminum alloys is the strength loss in heat affected zone (HAZ). As HAZ is subjected to one or more heating and cooling cycles during welding, the strength in this zone is decreased. The aim of this project is to apply a metallographic and mechanical experimental work in order to determine the micro-hardness and strength in weld cross section. Change of mechanical properties in heat affected zone by its distance from centerline of weld will be investigated and the exact limits of the zone subjected to strength loss will be determined.