Made available in DSpace on 2014-12-17T14:06:48Z (GMT). No. of bitstreams: 1 HaroldoRAM.pdf: 1140599 bytes, checksum: 95a046b646a7cfa0d6cf0153f138783f (MD5) Previous issue date: 2008-08-20 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / Titanium is a biomaterial widely employed in biomedical applications (implants, prostheses, valves, stents). Several heat treatments are usually used in order to obtain physical properties required to different applications. This work studied the influence of the heat treatment on microstructure of commercial pure titanium, and their consequences in growth and proliferation of MC3T3-E1 cells. Discs of titanium were treated in different temperatures, and characterized by optical microscopy, image analysis, wettabillity, roughness, hardness and X-ray diffraction. After the heat treatment, significant modifications in these properties were observed. Pattern images of titanium, before and after the cell culture, were compared by overlapping to analyze the influence of microstructure in microstructure and preferences guidance cells. However, in general, titanium discs that showed a higher residual strength also presented an increase of cells numbers on surface / O tit?nio como biomaterial ? amplamente utilizado em dispositivos biom?dicos (implantes, pr?teses, v?lvulas, stents entre outros). Diversos tratamentos t?rmicos s?o usualmente utilizados na obten??o das propriedades necess?rias para as diferentes aplica??es. Este trabalho estudou a influ?ncia desses tratamentos na microestrutura do tit?nio comercialmente puro e suas conseq??ncias no crescimento, forma e prolifera??o de c?lulas pr?-osteobl?stica. Para tanto foram utilizados discos de tit?nio submetidos a diferentes tratamentos e caracterizados por microscopia ?tica, an?lise de imagens, molhabilidade, rugosidade, dureza e difra??o de raios-X. Ap?s os tratamentos t?rmicos foram verificado modifica??es significantes nestas propriedades. Padr?es de imagens de superf?cies do tit?nio antes e ap?s a cultura de c?lula foram comparados atrav?s de sobreposi??o para analisar a influ?ncia da microestrutura na resposta biol?gica, n?o sendo verificadas correla??es entre a microestrutura e as prefer?ncias orientacionais das c?lulas. Entretanto de um modo geral verificou-se que os discos que presentaram maior estado de tens?o residual apresentaram tamb?m maior n?mero de c?lulas em sua superf?cie

Electron beam powder bed fusion (PBF-EB/M) has been attracting great research interest as a promising technology for additive manufacturing of titanium aluminide alloys. However, challenges often arise from the process-induced evaporation of aluminum, which is linked to the PBF-EB/M process parameters. This study applies different volumetric energy densities during PBF-EB/M processing to deliberately adjust the aluminum contents in additively manufactured Ti–43.5Al–4Nb–1Mo–0.1B (TNM-B1) samples. The specimens are subsequently subjected to hot isostatic pressing (HIP) and a two-step heat treatment. The influence of process parameter variation and heat treatments on microstructure and defect distribution are investigated using optical and scanning electron microscopy, as well as X-ray computed tomography (CT). Depending on the aluminum content, shifts in the phase transition temperatures can be identified via differential scanning calorimetry (DSC). It is confirmed that the microstructure after heat treatment is strongly linked to the PBF-EB/M parameters and the associated aluminum evaporation. The feasibility of producing locally adapted microstructures within one component through process parameter variation and subsequent heat treatment can be demonstrated. Thus, fully lamellar and nearly lamellar microstructures in two adjacent component areas can be adjusted, respectively.