Interface Fusion in Multi-Material Additive Manufacturing Technology

Multi-material additive manufacturing lets different materials combine in three-dimensional space. This makes it possible to create complex parts. These parts can have custom properties. Such properties meet specific functional needs. The quality of interface fusion directly affects the final part's performance and reliability. To solve this problem, many technical methods have been developed. This paper reviews interface fusion in three common multi-material additive manufacturing techniques. These techniques are material extrusion, material jetting, and photopolymerization. Based on their formation mechanisms, the study found and grouped the main types of interactions at these interfaces. These types include mechanical interlocking, molecular or atomic diffusion, and chemical bonding. The next sections explain in detail the characteristics of each interface type. The discussion includes design strategies to improve material compatibility. Relevant systems are ceramic matrices, thermoplastic polymers, and metal-ceramic composites. This paper gives a complete summary of active control methods for multi-material interfaces. Key techniques are optimizing multiple process parameters, adjusting material formulas, and planning coordinated printing paths for different materials. The conclusion shows the future research needed to overcome current challenges in the field.