Analise comparativa de dois processos de produção de materia-prima para tixoconformação : agitação mecanica e fusão parcial controlada

AUTOR(ES)
DATA DE PUBLICAÇÃO

2000

RESUMO

This work compares two processes, mechanical stirring (MS) and partial melting (PM) for the production of Al-4,5%Cu alloy with rheocast structure. For MS it was utilized continuous stirring ftom 640°C to 630°C, speeds of 1000 and 1500rpm., followed by isothermal stirring at 630°C during 5 and 15min. In the PM process two different raw materials (coarse and refined as-cast) were heat treated at 620°C and 630°C for 5 and 15min. Rheocast samples produced were submitted to metallografic analysis and microanalysis, for characterization of primary phase morphology (shape factor), Cu profile in the primary phase, microsegregation coefficient and average globulae size. Results show the best spheroidization and structural homogeneity in the rheocasts produced by PM of originally refined material. MS produced acceptable results only in the extreme conditions analyzed (maximum stirring speed and time/minimum stirring speed and time). PM using coarse structures as raw material produced the worse results, as well as RAM in the intermediate conditions of stirring time and speed analyzed

ASSUNTO(S)

fundição metais - processos de solidificação rapida processos de fabricação

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