Metal Glossary

Natural Ageing

The process that can alter the hardness and strength in some alloys after a period of time at ambient (room) temperature. It is caused by the spontaneous precipitation of constituents from a super-saturated solid solution. Generally it increases mechanical properties but can also, in some circumstances, cause loss of properties by over-ageing.

Related terms: Ageing, Age Hardening, Precipitation Hardening, Over-ageing

Non-Heat Treatable Alloy

An alloy, from the 1xxx, 3xxx and 5xxx series that are incapable of being strengthened by thermal treatment. These alloys gain their strength from cold-working.