Study On Microstructure And Properties Of The As-CAST And Annealing AlCoCrFeNiTi_x High Entropy Alloy

In recent years high entropy alloys become a hot research topic in the field of materials science due to its excellent properties.High entropy alloy breaks through the traditional concept of alloy design, approximative molar ratio of smelting, showing the multi-master effect, make the alloy crystal structure simplification, even precipitate nanocrystalline and amorphous materials, so that the performance of the alloy is greatly improved, which has the characteristics of high strength, high hardness, corrosion resistance and high temperature softening resistance.In this paper, the microstructure and mechanical properties of AlCoCrFeNiTix (x=0.5,1,1.5) high entropy alloy has been studied. The Ti content change to influence the structures and mechanical of AlCoCrFeNiTix high entropy alloy has been studied. And the effect of annealing treatment on Microstructure and properties of AlCoCrFeNiTix high entropy alloy also has been studied. The research content of this paper includes microstructure, microscopic structure, vickers hardness and compressive properties, etc. The results showed that:AlCoCrFeNiTix alloy is mainly composed of body-centered cubic (BCC1, BCC2) structure of solid solution phase, increased the content of Ti cause the BCC2diffraction peak enhance, alloy solid solution phase is dominated by BCC2, dendrite is more and more developed with the increase content of Ti, and also made the Laves phase appeared, the hardness of the alloys increased with the increase of Ti, but the plasticity decreased sharply, studies have found that when X≥1the alloy become very fragile. Intermetallic compound apeared after750℃annealing treatment, cause the compression performance declined sharply. The study found after annealing treatment alloy’s hardness changed little, alloy has good resistance to annealing softening. The annealing treatment is not obvious on the alloy compression performance improvement. It ultimately found that mechanical properties of cast AlCoCrFeNiTio.5high entropy alloy state is the most outstanding, so the alloy of X<1has certain research value.