Aluminium alloy property data in engineering design

Abstract: The vast amount of materials existing today and the fastdevelopment of new and modified ones make it favourable to haveaccess to computerised materials property data. The advantagesare fast access and the possibility to process datainstantaneous. The possibility to easily update the informationis another obvious advantage with computerised databasesystems. This is further enhanced by the growing number ofmaterials databases available on internet. To be able to handlethe rich information and make it a competitive advantage it isnecessary to use systematic methods for materials selection. Aproperty database system is presented which is based onsystematic materials selection theory. Systematic principlesfor pre-selection of materials groups and a concept for acomputerised database system forpre-selection isdescribed.Aluminium alloys are increasingly considered in load-bearingstructures. To further improve the competitiveness of aluminiumalloys as a structural material it is important to map out thebehaviour of welded structures completely. Welding inevitablyintroduces heat to the material and the effect on the materialproperties must be considered carefully in design. Differentwelding processes introduce varying amounts of heat to the basematerial and it is found that a process with little heattransfer, friction stir welding, gives beneficial mechanicalproperties in welded joints. Friction stir welded joints havenarrow HAZ widths and high as welded strength compared to MIGand TIG welding. It is concluded that there are models thataccurately predict the mechanical properties of weldments inaluminium alloys and that it is important to consider this indesign recommendations and rules. Load-bearing joints inthin-walled structures suffer from deformation of loaded platesleading to decreased loading capacity, and the development ofstress concentrations. Existing rules for both static andfatigue design give however safe results for thin-walledconstructions even though they do not consider these specialeffects.Keywords:Materials database, materials, selection,pre-selection, property data, welding, MIG, TIG, friction stirwelding, fatigue, loading capacity