3D Printing of Aluminum Alloys by Vat Photopolymerization Using Radical Inhibitors

Vat photopolymerization (VPP) is a potentially promising method for the 3D printing of aluminum alloy parts with complex structures, smooth surface, high resolution, and irrelevance to alloy type, etc. However, the slurry consisting of aluminum alloy powders, photosensitive resins, and dispersants exhibits low chemical stability and rapid degradation, hindering the application of VPP into 3D printing of aluminum alloys. In this work, a facile method is proposed to enhance the chemical stability of the slurry by introducing a radical inhibitor into the aluminum alloy slurry to mitigate the polymerization reaction of resins. The effect of radical inhibitor tert‐butylhydroquinone (TBHQ) on the stability of AA5052 slurry is investigated systematically. The optimal AA5052 slurry, containing 4 wt% of TBHQ and a solid loading of 55 vol%, exhibits no premature deterioration and remained stable for over 7 days. Complex AA5052 parts with high resolution, smooth surface, and tight bonding of interlayers are successfully fabricated by VPP. This work provides a convenient method for improving the chemical stability of aluminum alloy slurry for VPP and can be potentially extended to other metal slurry systems.