Laser Interaction with Carbon Fibre Reinforced Polymers

摘要

In the last decades a strong increase of use in Carbon Fibre Reinforced Polymers (CFRPs) in the production of structures and components occurred. In particular in the automotive and aeronautical sectors several manufacturers already replaced light alloy or high strength steel parts with composites but the use of composite materials is rapidly growing also in other industrial sectors. Composites offer great advantages not only in term of specific proprieties but also in term of “functionalization” of the products by means of the lay-up sequence optimization and consequently providing heterogeneous improved proprieties in the different three-dimensional directions. CFRPs with epoxy resin matrix, among the polymer composites, offer the highest mechanical proprieties in particular when combined with autoclave technology that represents the top standard. On the other side the production of composite materials parts, and particularly the autoclave processing, is still very far respect to conventional metal forming processes in term of production rates. For this reason a considerable effort is oriented towards research and development of the so called “out of autoclave” processing where a trade-off between mechanical proprieties and production rates are investigated. A real optimization of the whole process requires robust and efficient technologies also during those phases able to guarantee high production rates. Laser processing represents a typical technology able to guarantee high flexibility joined with high automation and high production rate not only for small but also for large series manufacturing. For all these reasons, a solid state continuous wave Laser has been used for machining thin sheets made by woven carbon fibre/epoxy resin Pre-preg of 160 g/mm2 (HR 3K 200 TEX carbon fibre with a 50% fibres in the warp and 50% in the weft directions). The aim was to investigate the interaction mechanism for removing the resin without damaging the fibres. Preliminary results in terms of process feasibility area were presented and discussed.