HIGH-STRAIN-RATE BEHAVIOUR OF CP-271 ALUMINIUM-LITHIUM

Abstract
Among advanced materials for transport, the low density aluminium-lithium alloy look particularly attractive for the aeronautic and aerospace industries. The main topic of this study is aimed to focus the correlation of the fundamental mechanisms with respect to the high strain-rate behaviour of the CP-271 aluminium-lithium alloy. Specimens have been deformed in compression and torsion at strain-rate range from 10^-3s^-1 to 10⁴s^-1 ; the dynamic testing is done by the split-Hopkinson bars method. Comparison of the results between quasi-static and dynamic behaviour is done. CP-271 aluminum lithium alloy is quite sensitive to strain-rate. The testing results and the microscopic observation prove that the heat-treatment conditions have a great influence on the dynamic rupture property of the aluminium lithium alloys. These basic mechanical properties and microstructure relationships will help to a better comprehension of the behaviour of thèse Al-Li alloys. In addition, it helps to set up a guideline for the sélection of a more promising microstructure for a better impact strength of the material.