Effects of Elements on the Microstructure and Mechanical Properties of AlCoCrFeNiTi High-Entropy Alloys

AlCoCrFeNiTi high-entropy alloys (HEAs) have attracted much attention because of their excellent mechanical properties. Here, we systemically studied the effects elements on microstructure and properties HEAs. The results showed that phase composition morphology are significantly affected by elements. With increasing Ti addition, lattice parameters solid solution increased slightly, distortion occurred. Al changes crystal structure FCC to BCC reduces energy alloy. obviously increases with content. However, excessive Al, Cr promote formation intermetallic compound phases, while Ni, Fe Co transformation alloy into a solution. HEAs closely related morphology. When consist only ductility strength greatly improved. presence an in can reduce configurational entropy adjacent solutions, thus reducing strengthening effect solutions. Additionally, different microstructures show deformation mechanisms. + cellular structures is uniform presents great plasticity strength. cellular-structure contain equiaxed BCC, thick lamellar BCC/FCC or cracks tend occur propagate along boundary due local nonuniform deformation. For dendrite structures, after initiation at boundary, crack does not easily spread but causes interdendritic crack.