Development of a New Laser-Assisted Additive Manufacturing Technology for Hybrid Functionally Graded Material Composites

This paper investigates a new technology to create functionally graded material (FGM) by additive manufacturing (AM). In particular, this paper focuses on creating graphene-polymer composite FGM by laser-based sintering processes. Graphene-polymer composites have received high attention in AM due to their excellent electrical conductivity, thermal stability and mechanical strength. However, AM of the graphene-polymer composites has a huge challenge to overcome. The heterogeneous materials should be mixed properly, and it is not easy to achieve the desired composite characteristics solely by changing the mass ratio of graphene. This paper shows a newly developed laser-assisted AM system for the graphene-polymer composite FGM by laser-based sintering processes. The paper also describes two methods of material integration: mixing graphene and polyethylene powders before sintering, and depositing the different material powders separately and sintering them. This study identified that the two methods led to different mechanical and electrical properties of the created parts. Thus this paper demonstrates the possibility to create quite useful hybrid (mechanically and electrically) FGM composites.