8.3 - Standardisation & designation of aluminium

What are the 2 main groups of aluminium alloys?

What are the differences between them?

What are their names in EN (European norm)?

Casting alloys (fonte)

→ designed for casting

→ good castability (flow & mold filling properties)

→ lower strength & ductility but often higher complexity in shape

→ EN AC

Wrought alloys (forgés)

→ designed for mechanical working

→ higher strength & ductility due to work hardening & heat treatment

→ better formability

→ EN AW

What are the 2 ways of designating & classifying aluminium alloys in European norm EN?

• Short names

EN [AW or AC] - [chemical symbols] [alloy modification]

• Material numbers

EN [AW or AC] - [code number] [alloy modification] [variety number] [national variants]

How do we read the short names of aluminium alloys?

EN [AW or AC] - [chemical symbols] [material condition]

→ AW = aluminium wrought / AC = aluminium casting

→ chemical symbols represent the main alloying elements in the alloy and their proportions

→ material condition indicates the casting process & the material condition

E.g.

EN AC- AlSi6Cu

→ aluminium casting, alloy with 6% silicon & unspecified but smaller amount of copper

EN AC- AlCu4MgTi

→ aluminium casting, alloy with 4% copper, & unspecified but smaller amounts of Mg & Ti

How do we read the material numbers of aluminium alloys?

EN [AW or AC] - [code number] [alloy modification] [variety number] [national variants]

→ AW = aluminium wrought / AC = aluminium casting

→ code number represents the main alloying elements

→ alloy modification = number indicating a specific variant of the alloy

→ variety number = number indicating the variety

→ national variants: 2 letters indicating respectively the casting process & the material condition

Note: code number + alloy modification = chemical composition