Research on shape memory alloy honeycomb structures fabricated by selective laser melting additive manufacturing

Abstract

Active honeycomb structures made of shape memory alloys (SMAs) have drawn worldwide attention for their potential applications in smart morphing wings. However, the manufacturing of SMA honeycomb structures via conventional processes is somewhat limited, especially when complex designs are needed. In this paper, selective laser melting (SLM) additive manufacturing was used to create NiTi-based SMA honeycomb structures that could be used for smart morphing wings. The influence of process parameters on structure precision, relative density, transformation temperatures, in-plane tensile deformability capacity and active deformation response were investigated systemically. The results show that high quality honeycombs with a relative density of 99.5% can be fabricated by the optimum process parameter with an energy density of 139 J·mm−3. Most importantly, the honeycombs fabricated with the optimum process parameter exhibit good in-plane tensile deformability capacity with a maximum strain of 62.3%, and show excellent active deformation response with an actuation strain of approximately 13% with functional stability. This research will contribute to the design and fabrication of SMA honeycomb structures based on SLM additive manufacturing, providing novel ideas for the future development of smart morphing wings.