A Novel Concept to Design Machine Tool Structures using Multifunctional Materials

This paper reports on a novel concept to design and realise machine tool structures focussing on improvements related to the thermal and dynamic stability of the machine. These involve a large reduction in the mass of moving machine parts and an increase of their stiffness and damping to obtain excellent static, dynamic and thermal stability of the structures, features becoming a "must" to ensure excellent results in terms of technological and cost-saving design effectiveness. The authors have carried out a thorough study of, and testing validation on, multifunctional material prototypes for the moving parts of Ultra High Precision (UHP) machine tools. Two types of multifunctional materials are considered: Aluminium foams (AFS), based on sandwiches with cores made of metal foam (open cells), and corrugate-core sandwich panels. Both solutions have incorportated phase change materials (PCMs) in order to maintain the thermal stability when the environmental temperature changes. Additionally, the hybrid materials reduce the weight of the structures, increasing damping performance and guaranteeing an excellent stiffness. The study presents the experimental results and a comparison of the two implemetation materials suggested.