EUROPEAN CONGRESS AND EXHIBITION ON ADVANCED MATERIALS AND PROCESSES - EUROMAT 2021

Engineering alloys, such as steel, are often produced by the combination of several elements with one to be the base material, such as iron, with a mass contribution of about more than 70%. In the past couple of decades, a new group of alloys, known as high entropy alloys (HEAs), have been introduced that contain different elements with an equal mass contribution that could deliver considerably enhanced mechanical and functional properties compare with conventional alloys. Due to the demand in transportation industries to utilize novel light-weight materials, the development of a new generation of light-weight alloys has also brought widespread interest in HEAs to the materials science and engineering communities, particularly for the purpose of saving energy and raw materials.
In the present investigation, AlCrFeMnTi light-weight high entropy alloys (LWHEAs) were prepared by mechanical alloying followed by spark plasma sintering. The powders were produced by high energy ball milling (HEBM) after 20 h with a speed of 400 rpm. SPS was performed at 1100 ℃ with a uniaxial pressure of 30 MPa. The heating rate was 100 ℃/min up to 1100 ℃. The maximum temperature and pressure were held for 10 min, before allowing the furnace to cool down.
Furthermore, the as-sintered sample was annealed at 1000℃ under a vacuum atmosphere for 2h and slowly cooled inside the furnace till the room temperature. The phase and microstructure of the as-sintered and annealed samples were studied by SEM and XRD and the results were compared with CALPHAD calculations.
The TOPAS 4.2 was also employed for the phase fraction calculation by Rietveld refinement analysis of XRD spectra. Besides, mechanical properties, including hardness, modulus of elasticity, and stress-strain response, were measured using the nanoindentation method.