High power laser beam melting of Ti6Al4V on formed sheet metal to achieve hybrid structures

Abstract

ABSTRACT Motivated by the desire to combine the advantages of tw o manufacturing concepts, namely Additive Manufacturing and sheet metal forming, the concept of hybr id processes emerged. Laser Beam Melti ng process with its characteristic layer by layer fabrication met hodology has already been proved to be successful in fabricating fully dense 3D structures with micro sized Ti-6Al-4V powder. The presented research focuse s on direct fabrication of Ti-6Al-4V Additive Structures on a thin pre-formed Ti-6Al-4V sheet metal substrate. In the state of the art La ser Beam Melting process, fabrication of solid structures is done on a support structure attached to a thick conventionally manufactured base plate. The state of the art process also uses a 200°C pre-heating of the fabrication platform in order to reduce the effect of heat induced stresses on the fabricated structures. Within the hybrid fabrication concept, 3D struct ures are directly fa bricated on a thin sheet metal and the thermodynamic conditions are significantly different in comparison to the conventional process. The research aims at understanding the fundamental aspects of the interaction between the formed sheet metal and additive structure determines the corres ponding mechanical characteristics. The inter action process during the fabrication exposes the alloy locally to non-optimum thermal cycles and the research therefore aims to understand the various influencing factors involved during the fabrication process. The system technology modifications required to achieve the aimed fabrication are also discusse d in the presented research.