In-situ TiC particles strengthen and ductilize Fe1.2MnNi0.8Cr high entropy alloy

TiC particles reinforced Fe1.2MnNi0.8Cr high-entropy alloy matrix composites (HEACs) were prepared by vacuum induction melting. The effects of Ti and C additions on the microstructural evolution and mechanical properties of the new composites were investigated. It was found that by adding Ti and C, not only were TiC particles produced in situ, extra solid-solution effect was also introduced to strengthen the HEA matrix. As the volume fraction of TiC increased, both the ultimate tensile strength and the percent elongation of the composites first increased then decreased while the hardness increased and remained high. The ultimate tensile strength of the composites was found to reach 856 MPa when the content of TiC was 5.9 vol %, which is 30% greater than that of the HEA base. At the same time, the percent elongation was found to be 34%, an increase by 42% as compared to the HEA matrix. Due to the combined effects of Orowan mechanism, load transfer and solid solution strengthening, the new composites have achieved an unity of high tensile strength and good plasticity.