Effect of Si/Ti additions on physico-mechanical and chemical properties of FeNiCrCo high entropy alloys manufactured by powder metallurgy technique
(1. Mechanical Design and Production Engineering Department, Faculty of Engineering, Cairo University, Giza 12613, Egypt;
2. Mining, Petroleum and Metallurgical Engineering Department,Faculty of Engineering, Cairo University, Giza 12613, Egypt;
3. Department of Chemistry, Faculty of Science (Girls), Al-Azhar University,P.O. Box: 11754, Yousef Abbas Str., Nasr City, Cairo, Egypt;
4. Powder Technology Division, Manufacturing Technology Institute, Central Metallurgical R&D Institute, P.O. Box. 87, Helwan 11421, Cairo, Egypt)
2. Mining, Petroleum and Metallurgical Engineering Department,Faculty of Engineering, Cairo University, Giza 12613, Egypt;
3. Department of Chemistry, Faculty of Science (Girls), Al-Azhar University,P.O. Box: 11754, Yousef Abbas Str., Nasr City, Cairo, Egypt;
4. Powder Technology Division, Manufacturing Technology Institute, Central Metallurgical R&D Institute, P.O. Box. 87, Helwan 11421, Cairo, Egypt)
Abstract: FeNiCrCoSix and FeNiCrCoTix (x=0, 0.3, 0.6, and 0.9 wt.%) high entropy alloys (HEAs) were prepared via the powder metallurgy technique. A homogenous distribution of the elements in all alloys due to the formation of a solid solution phase is observed. The density and hardness of the prepared HEAs are improved by Si and Ti additions, compared to FeNiCrCo HEA. The wear rate of the prepared alloys was studied at different loads and the results indicate that the alloys that contain 0.3 wt.% Si and 0.9 wt.% Ti have the lowest wear rates. X-ray diffraction, SEM, and EDX were used to understand the phases, grain sizes, and microstructures in different investigated HEAs. The effects of Si and Ti content on the corrosion behavior and surface morphologies of sintered FeNiCrCoSix and FeNiCrCoTix HEAs were studied by immersion in H2SO4, HNO3, and HCl solutions. Uniform corrosion and localized pitting are observed in different sizes in the corrosive media used. Because of the smaller pit size and the reduced pit density, the FeNiCrCoSi0.3 HEA has an excellent microstructure.
Key words: FeNiCrCoSix alloy; FeNiCrCoTix alloy; high entropy alloys; powder metallurgy; corrosion behavior