January 2013
How Matching Can Cause Distortion In Aluminium Alloys
An alloy is created when aluminium is combined with another metal, commonly copper, silicon, zinc or magnesium. As the alloy will expand to a greater degree when it is heated than pure aluminium will, there is a great risk of distortion occurring to the metal during the machining and processing stages. So, how can we avoid this distortion occurring?
Choose aluminium alloys that have matching coefficients of expansion, as this will ensure that the metal expands uniformly as it is heated, helping to prevent distortion from occurring.
Use stress relieved alloy instead of one that has been untreated. As the metal has had its stress relieved via an additional compression or heat treatment, it won’t warp during machining.
Avoid heating up the metal multiple times or heating it unevenly when processing. You should also avoid using thinner components, as these are also at greater risk of warping.
Use slow quenching materials to cool the aluminium slowly during the machining process, as this can also help to prevent distortion and even possible warping.
Choose welds that possess the same coefficient of expansion as the alloy, as this will prevent the chances of deformation occurring during the welding process.
Whilst distortion can be difficult to avoid when working with aluminium alloys, there are a number of things that you can do to help minimise the chances of this issue arising. Matching is certainly the most preferable solution (as it covers a few areas of aluminium machining and processing) but, as you can see, there are also a number of other helpful tips.
