INTEMA   05428
INSTITUTO DE INVESTIGACIONES EN CIENCIA Y TECNOLOGIA DE MATERIALES
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Mechanical testing of micro moulded plastic parts by nanoidentation
Autor/es:
OLIVEIRA, M.S.A.; NETO, V.; FRONTINI P.; ZHILTSOVA T.V.; DAGA B.
Lugar:
Ghent
Reunión:
Conferencia; International Conference on Polymers and Moulds Innovations - PMI2016; 2016
Institución organizadora:
Ghent University
Resumen:
Weld lines are unavoidable where two flow fronts come together. They may result in purely cosmetic imper-fections, but also may represent part failure if placed in an area on the plastic highly subjected to stress during service. Qualitative assessment of these structural and cosmetics defects is normally accomplished by conven-tional mechanical characterization, destructive by nature, such as tensile testing or dynamic mechanical analy-sis (DMA). Nano indentation offers the possibility for quick quasi-non-destructive in-situ testing, allowing for monitoring the changes that occur in the surface layer of a plastic micro part and hence derive relationships be-tween the process variables and product characteristics. In this study, a methodology for the assessment of the superficial properties: hardness H and reduced Young's modulus Er of micro-molded parts was developed. The micro parts, molded from Polyoxymethylene with two different sets of processing conditions were tested throughout the entire length and in the vicinity of the welding line. The observed hardness H and reduced Young's modulus Er, in both cases, suggest that there is a steady increase in both values along the weld line from the adjoining flow front point at the inner side of the micro part towards the outer edge. In addition, H and Er were found out to vary consistently with the alterations induced on the processing conditions.