Laser processing of CoCrFeMnNi high entropy alloys

• Autor(a) principal: Videira, Frederico Victorino Galvão
• Data de Publicação: 2022
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10362/157162
• topic: high entropy alloys; laser processing; additive manufacturing; ductility; Domínio/Área Científica::Engenharia e Tecnologia::Engenharia dos Materiais

High entropy alloys (HEAs) differ from conventional alloys because of their number of element constituents. These alloys conjugate 5 or more elements with the aim of taking advantage of these elements’ properties in one new material. The subject of this thesis addresses the high entropy alloy – CoCrFeMnNi – when submitted to two kinds of laser processing, one-sided (HEA 1) or two-sided (HEA 2), that will affect the material’s microstructure, and consequently its properties. The main goal is to understand how the laser processing modifies the samples’ microstructures and how they behave after the processing. Grain structure will obviously be affected, so another objective is to study its evolution and effect on the material’s hardness and mechanical properties. Laser processing was carried out, microstructural analysis, including optical microscopy (OM) and backscattered electron diffraction (EBSD) were also performed, some Vickers hardness tests and, finally, tensile tests combined with a scanning electron microscopy (SEM) analysis of the fracture surfaces. (...)