Mechanism of Pure Copper Binder Jetting Additive Forming and Sintering Densification

Abstract:

The printing process and the debinding sintering process were carried out step by step to realize the pure copper processing with high laser reflectivity and high thermal conductivity. The process parameters of pure copper binder jetting additive manufacturing were studied. The effects of powder layer thickness and inkjet density on green parts forming performance were studied. At the same time, the effects of sintering atmosphere and sintering temperature on the densification process of the parts were studied. The results show that the combination of powder layer thickness of 75 μm and inkjet density of 50% can ensure the density and compression strength of green parts, resulting in high dimension precision and high surface quality. The driving force in hydrogen atmosphere is stronger than that in vacuum, and the surface oxide layer can be effectively reduced by the introduction of hydrogen. The compactness of sample treated at 1060 ℃ is 77.70%, the carbon residue forms pores to restrain the sintering process, and the compactness of sample treated at 1070 ℃ is 93.94%. It points out the direction for further optimizing the manufacturing process of binder jetting with pure copper.