Metal 3D Printing and Casting

Abstract

Metal 3D printing is the hot new frontier in 3D printing. 3D printing in metal is inherently harder than printing in plastic because of the far higher temperatures involved in melting (or, at least, sintering) metal at some point in the process. However, some clever crossovers with the technologies behind metal injection molding (MIM) are bringing a flurry of lower-cost metal 3D printing options to market. In this chapter, we will survey the current state of the art in metal printing. We then talk about casting metal parts as an alternative-that is, printing a part in plastic and using the plastic part to create a mold for metal. This field is changing very rapidly, so there may be even more options by the time you read this. Metal 3D Printing Technologies Metal 3D printing can be broken into three categories: direct laser metal sintering (DMLS), binder-jetting methods, and what we will call "filament-like" printing, which some manufacturers refer to as "bound powder" printing. The latter two owe a lot to metal injection molding, so first we will have a little sidebar about that technology.