Magnetic field-assisted DLP of CIPs/resin composites: Mechanical properties, anisotropic magnetic performance and wear behavior

Fabrication of composites with anisotropic properties by additive manufacturing has drawn great attention in recent years. Magnetic-assisted digital light processing (DLP) of micron-scale carbonyl iron powders (CIPs)/resin composites (MACRCs) with tunable microstructure and magnetic properties can be used as smart sensors/actuators in soft robots, aerospace/automobile applications and drug delivery devices due to their complex geometries and fast activation response. However, anisotropic, wear and mechanical properties remain unclear for MACRCs. This work aims to investigate their microstructure-function-wear resistance relationship. Photosensitive resin and CIPs with a concentration up to 5 wt% were prepared to print samples with different anisotropic magnetic properties, using magnetic field-assisted techniques. The results show that addition of CIPs in resin can still maintain good printability, while the mechanical properties deteriorate slightly as the micro-size CIPs reduced the interface bonding strength. Anisotropic magnetic properties were studied using the magnetization tests. In addition, wear tests showed that the coefficient of friction of samples decreases from 0.4938 (pure resin) to 0.4066 (MACRCs with 5 wt% CIPs), indicating improved wear resistance by the addition of CIPs. This work demonstrated that tunable magnetic and mechanical properties can be achieved by manipulation anisotropy of the magnetic nanoparticles using external magnetic field.