Abstract
	The hot forming of metals is carried out by means of various laboratory tests. The behaviour of the metal depends on the precise combination of the parameters temperature-deformation-time-stress factor. The hot workability test is usually done by performing the material under the conditions where the analysis of the stress-strain relation is easily carried out. The torsion test is of frequent use for assessing hot workability of metals. The stress-strain curves are the result of mentioned laboratory test. Formability evaluation of aluminium alloy EN AW 2014 by means of torsion test was performed. Torsion tests were registered a value of the torque and the number of revolutions, which graphically plotted to relationship of stress-strain curve. Every curve shows a rapid increase in the stress to a peak value, followed by a gradual decrease towards a steady state regime which is not reached before fracture. From achieved results are investigated, that with increasing deformation temperature decreased formability of investigated materials. The stress-strain curves showed the softening after achieved peak value of stresses. In all cases the relative softening is increasing trend with increasing deformation temperature. The final deformation (the number of revolutions) during continue test provided the information about formability of investigated material. For the better understanding of material formability was carried out the relationship fracture deformation ef on temperature T and deformation rate , respectively.