Fraunhofer Institute for Production Technology
Fraunhofer Institute for Production Technology

Project Overview

Initial Situation

Fiber reinforced polymers (FRP´s), also known as composites, are inhomogeneous materials built up by a combination of oriented reinforcement fibers and polymeric matrix materials. Compared to conventional materials like steel or aluminum, the use of FRP´s enables a significant weight reduction up to 70%, while at the same time it shows improved static (stiffness, strength), dynamic (damping) and chemical (corrosion) characteristics. Despite the listed potentials, the extensive use of FRP materials is mainly limited to high-end application from the aerospace industry and the segment of luxury vehicles. However, in the near future, the use of fiber reinforced polymers, particularly in combination with common metallic materials, will also increase in price-driven mass production industries.

Challenges for drilling

The joining efficiency of bolted joints, or rivets, highly depends on the quality of the machined holes. However some specific characteristics of composite laminates such as inhomogeneity, anisotropy, the layered structure and the extreme abrasiveness of fiber reinforcements present a considerable challenge for processing operations like milling and drilling.

Objectives and approach

The purpose of the VibroCool project is a system and process development for an advanced drilling technology of fiber reinforced polymers (FRPs) and FRP metal stacks, aiming for a future strengthening of the composite manufacturing community. Vibration assisted machining, the use of cryogenic cooling or lubrication (two channel feed through of aerosol and liquid CO2), and optimized poly crystalline diamond drills will be combined to reach the highest possible increase in cutting performance. For the realization of the planned technology, single system components as well as their interfaces will be developed and integrated within a sophisticated machine tool. Parallel process technological investigation will guarantee an optimal utilization of the VibroCool technology’s potential.