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A specific technical expertise is required to machine metal–matrix composites (MMCs). It is well known, from the literature data, that MMCs cutting involves high costs and high machining times due to excessive tool wear and possible subsurface damage. In recent years, the emphasis of research has focused on understanding the mechanics and mechanisms that are responsible for the behaviour of MMCs during the material removal process. These kinds of studies would be the most effective way of understanding the machining characteristics and deformation behaviour of the material. This work is a contribution to understanding the effects of two antagonistic phenomena that determine MMCs behaviour during the cutting process, such as the thermal softening of the matrix and the matrix hardening due to strain. To this end, a simplified model that describes the behaviour of the reinforcements beneath the machined surface is proposed and experimentally validated. [ABSTRACT FROM AUTHOR]

The resin transfer moulding (RTM) process is a low-cost process for the production of parts of composite material. However, the economic convenience is lost when large components should be produced, because of the high tooling cost. The step milling of a resin master and the subsequent deposition of a nickel shell could be a valid alternative for the fabrication of an RTM mould. So far, information about the quality of this method of fabricating RTM moulds is lacking, thus more efforts are needed to quantify the error induced by the manufacturing sequence. In order to control the whole process and to assess the quality of the manufactured part, the dimensional deviation due to single manufacturing steps is evaluated for a reference part. Both traditional pointwise measurements and contactless scanning are used for dimensional inspection. [ABSTRACT FROM AUTHOR]

Continuous Filament Fabrication (CFF) is the additive manufacturing process for producing material reinforced with long fibres. Differently from other processes, CFF allows producing components in composite materials without using tools, moulds or post-processing operations and with a strengthened area only where it is strictly required. This innovative way of producing composites makes a new design approach necessary for better exploitation of the material. This work presents a preliminary study based on 3D Finite Element (FE) method to predict the mechanical behaviour of composite materials fabricated by CFF. With this aim, a FE model is developed to determine the actual material properties in terms of longitudinal, transverse and shear modulus. Comparisons between experimental and numerical tensile results at different fibre orientations validate the model. The robustness of the proposed approach is confirmed by the comparison with the experimental characterisation of composites produced with two different fibre reinforcements, Carbon and Kevlar®. • CFF is the only additive manufacturing for reinforced materials with long fibres. • The new approach to composite material production needs of new design tools. • A methodology is developed to determine the properties of a material printed by CFF. • The 3D finite element method and experimental tensile specimens are used. • Experimental analyses with Carbon and Kevlar fibres prove the model robustness. [ABSTRACT FROM AUTHOR]