Multi-layer Materials. Qualitative Approach of the Process

The increasing part of multi-layer materials in the aerospace industry has created new machining problems. Indeed it is very difficult to machine these materials, particularly to drill them because they consist of materials with very different nature stacks, as strongly heterogeneous materials, such as carbon fibre composite, and materials monolithic, such as aluminium and titanium. The choice of cutting tool should be a compromise, to withstand high temperature involved during titanium drilling, as well as highly abrasive carbon fibre, while allowing the acquisition of drilling of aircraft grade. This article, as a first step, presents a formalisation of multi-layer materials drilling isolating quality criteria, as well as the concept of stacking. Indicators have been defined in order to characterize these two basic concepts of multi-layer materials drilling, which are quality and stacking. In a second part, a presentation of the structure of an experimental multi-layer model will be done by identification of its basic parts.