The implant’s surface is responsible for direct interaction with the human body. For cases where osseointegration must be favored and the risk of bacteria proliferation is lower, rough surfaces are more suitable, while for implants where the risks are higher, a reduced surface roughness is required. This study aimed to analyze and produce different surface finishes on samples of Ti-6Al-4V alloy produced by additive manufacturing technique of Direct Metal Laser Sintering (DMLS). Surfaces of the samples were analyzed in the as-built condition, after blasting, after chemical etching, after electropolishing and two different combinations of these methods. The surfaces were studied using the technique of scanning electron microscopy, and surface roughness and mass measurements. The lower roughness value was obtained after a combination of blasting and chemical etching. Blasting results in a surface with uniform roughness while chemical etching cleans the surface and reduces its roughness.

Resumo: A Mina de Casa de Pedra, localizada no extremo sudoeste do Quadrilátero Ferrífero, MG, foi submetida a uma investigação estrutural de detalhe, através da qual foi possível conhecer o seu acervo de estruturas, assim como a sua evolução tectônica. Neste estudo procurou-se entender de que forma o arcabouço estrutural da mina influencia nas variações dos atributos intrínsecos de seus componentes: mineralogia, porosidade, granulometria e textura. Foram obtidos os seguintes resultados: unidades expostas na área da mina e arredores foram submetidas a três eventos deformacionais; as frentes de lavra Corpo Oeste e Corpo Principal estão situadas em distintos domínios estruturais e seus minérios exibem diferentes atributos mineralógicos; o minério de ferro proveniente do Corpo Oeste tende a ser mais rico em hematita especular e goethita, com porosidade média de 17%, enquanto que o Corpo Principal tende a ser constituído predominantemente por hematita granular e magnetita, com porosidade média de 20%. Desta forma, pode-se concluir que o arcabouço estrutural condiciona significativamente as características composicionais, texturais e microestruturais dos minérios de ferro.

Abstract: The Casa de Pedra mine, located in the southwestern portion of the Quadrilátero Ferrífero (Iron Quadrangle), Minas Gerais state, Brazil, was subject to a detailed structural investigation, allowing the characterization of its tectonic evolution. The main goal of the study was to check in what extent tectonic structures control the iron ore properties such as mineralogical composition, porosity, grain size and texture. We obtained the following results: rocks units exposed in the mine and surrounding areas underwent three deformational events; the Western and Main ore bodies of the Casa de Pedra mine are located in distinct structural domains, which exhibit different mineralogical attributes; iron ores from Western body tends to be richer in specularite and goethite, and show 17% porosity, whist the Main body is made up mainly of granular hematite and magnetite, with 20% porosity. We concluded that tectonic structures indeed exert a significant control on mineralogical composition, textures and microstructures of the iron ores.