Avaliação da replicagem de moldes torneados com ferramenta de diamante usando prensagem a quente em polimetilmetacrilato (PMMA) / Evaluation of the replication of molds generated from single point diamond turning using hot embossing in polymethylmethacrylate (PMMA)

AUTOR(ES)
DATA DE PUBLICAÇÃO

2006

RESUMO

In this work, different types of microstructures were generated by single point diamond turning and microindentation for will replicated through the hot embossing. Tests were carried to evaluate the generation these microstructures by two distinct methods: micro-deformation and micro-machining, planned to observe the replication of the mark generated by the Vickers indenter (Pyramidal) and the latter by material removal (single point diamond turning). A review on several manufacturing processes applied to replication of microfeatures, is presented. The materials used as mould and replication workpiece were electroless copper and polymethylmethacrylate (PMMA), respectively. Initially, the machinability of electroless copper was evaluated under different cutting conditions to determinate appropriate turning parameters to obtain very fine surface finish (roughness). It was observed that for f = 10 microns of revolution (feed rate) and ap = 5 microns (depth of cut), the surface presented the roughness’ lowest value, i.e., 2,81 nm to medium roughness (Ra) and 13,4 nm to theoretical roughness (Rt). Moreover, it was observed that the microstructure of the material plays a fundamental role on roughness, because of the elastic recovery of grains due to the anisotropy of the polycrystalline structure of copper. The microfeatures generated were the following: a) spherical lens, b) sinusoidal profile and concentrical grooves. The results showed that it is feasible to reproduce, with good agreement, the microfeatures by means of hot embossing. It was observed that thin edges and fine surfaces with roughness around 10 nm rms were well replicated.

ASSUNTO(S)

prensagem a quente single point diamond tool ferramenta de diamante cobre eletrolítico electroless copper ultra precision turning microestruturas ópticas optics microstructures hot embossing polymethylmethacrylate polimetilmetacrilato torneamento de ultraprecisão

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