Study and Control of Properties and Behaviour of Al–Mg–Si Alloys by Application of Statistical Design of Experiments

Abstract

The strengthening characteristics of Al–Mg–Si alloys have been studied by using the statistical design of experiments. In particular the effect of composition and heat-treatment on the mechanical properties and brittleness of Al–Mg–Si alloys, containing silicon up to 1.00% and magnesium up to 2%, has been investigated.
Equations have been developed connecting the variations in composition and heat-treatment parameters for these alloys with the mechanical properties. Detailed analysis of coefficients of interactions give some insight into the role of different variables in determining the properties of these alloys.
The interpretation of the regression equations bring us to the same broad conclusions as have been predicted by earlier workers after extensive experimentation. The strong interaction between Mg and Si in these alloys has a marked influence on the strengthening behaviour of these alloys and makes the equations nonlinear.
As such, the second order design has been found to be better in describing the response surface and, therefore, is more suitable to these alloys for optimization purposes.