What Is Hybrid Manufacturing?

While “hybrid” can be used to describe many combinations of subtractive and additive manufacturing (AM), “hybrid manufacturing” most often refers to the combination of machining and 3D printing, typically metal. 

Hybrid systems most often consist of a machine tool such as a mill or lathe, or a robot arm, that is equipped with a directed energy deposition (DED) head for depositing metal powder or wire. Other systems are available that combine machining with  powder-bed fusion (PBF). There are also hybrid systems for processing polymers, typically using material extrusion as the additive process. 

How Does Hybrid Manufacturing Work?

One of the most common methods of hybrid manufacturing is to apply additive and subtractive processes in sequence. For example, the machine could 3D print a near-net shape component that takes the place of a conventional casting or forging. Then, its subtractive capabilities could be applied to finish this part. 

It is also typically possible to alternate between additive and subtractive in-process. For instance, the system could machine a blank, 3D print needed features onto the part, and then machine those 3D printed features. Or, machining could be applied to finish internal features as they are printed. 

What Materials Can Be Used?

Depending on the system, nearly any metal available in a wire or powder format could be 3D printed. These include aluminum, cobalt chrome, copper, Inconel, stainless steel, tool steel and titanium, among others. One advantage of hybrid metal systems is that they often enable applying dissimilar metals to the same part, for instance cladding with Inconel for strength or incorporating copper for heat transfer. 

Polymer systems often use fused filament fabrication (FFF) and so many different polymer filaments can be applied. There are also large-scale hybrid systems that use injection molding pellets and may be compatible with composite reinforced polymers. Hybrid polymer systems can also apply multiple materials, for instance to create an overmolding effect. 

Why Use Hybrid Manufacturing?

Hybrid manufacturing offers a number of benefits over machining or 3D printing alone. Because of additive’s ability to add material to existing parts, it is possible to build up and repair damaged parts, or to reduce machining work by starting with a smaller blank and adding material just where it is needed. 3D printing also allows for the use of multiple materials in a single part, which makes it possible to clad weaker metals for greater strength, add copper to aid heat transfer or save money on material by applying expensive metals only where they are needed. 

When additive is combined with machining in a hybrid system, it is possible to 3D print and finish a part in a single setup. This approach reduces error because the printed part does not have to leave the build envelope and be reset on a separate machine. It is also possible to alternate printing and machining to finish internal features, such as conformal cooling channels for injection molds, or features that would be inaccessible in the completed part.