Mechanical Properties Improvement of AlCrFeNi2Ti0.5 High Entropy Alloy through Annealing Design and its Relationship with its Particle-reinforced Microstructures

High entropy alloy has attracted increasing attentions. However, to enhance the alloy strength often leads to impairment of the ductility, or vice versa. Here we reported a heat treatment approach on AlCrFeNi2Ti0.5 high entropy alloy, which can elevate the strength and ductility simultaneously. An ingot of AlCrFeNi(2)Ti(0.)5 weighing 2.5 kg was firstly fabricated by medium frequency induction melting. Then samples from the same height of the bulk ingot were annealed for 6 h at 600, 700, 800 and 1000 degrees C, respectively. After 1000 degrees C annealing, an optimal microstructure was obtained by using our approach which can make some precipitation particles distribute homogeneously in the dendrite interior while keep the interdendrite structure as a single solid solution phase. The mechanical test on this AlCrFeNi2Ti0.5 alloy sample showed that, the compressive fracture strength sigma bc was increased by about 600 MPa and the plastic strain epsilon p was doubled, compared with those of the as-cast sample. Our approach can be readily adapted to large-scale industrial production of high entropy alloys with high strength and ductility by proper annealing treatment. Copyright (C) 2015, The editorial office of Journal of Materials Science & Technology. Published by Elsevier Limited. All rights reserved.