engleski

The influence of solution hardening on microstructure and mechanical properties of Al- 2.2Mg-2.1Li alloy

The microstructure and mechanical properties of aluminum (Al) alloy containing 2.2 wt.% of magnesium (Mg) and 2.1 wt.% of lithium (Li) were analysed in as cast and solution hardened condition. The Al-2.2Mg-2.1Li alloy was synthesized by following procedure: melting under vacuum and casting into a permanent steel mould without protective atmosphere. Afterwards, obtained samples were solution hardened at 520°C for four hours and quenched in water. Metallographic analysis consisting of light and electron microscopy as well as X-ray diffraction was used in order to estimate the behaviour of microstructural constituents during solution hardening and thermo-mechanical compression testing performed on Gleeble 1500 D machine. The initial metallographic analysis of the samples in as cast condition indicated the microstructure of permanent mould castings. Although, solution hardening eliminated the difference in grain morphology with chill, columnar and equiaxed zone, it led to the recrystalization and grain growth. Consequently, lower strength properties were achieved after solution hardening. Microstructure of the samples in as cast condition showed significant texture development during compression testing. In the solution hardened samples compression led to the planar slip band formation and crack propagation. The lower strength value and results of metallographic analysis pointed to inadequate heat treatment regime of Al-2.2Mg-2.1Li alloy.

Al-2.2Mg-2.11Li alloy, solution hardening, microstructure, mechanical properties

nije evidentirano