Technology overview

- Hi. Welcome back and welcome to Youngstown, Ohio. I'm here at America Makes, the National Additive Manufacturing Innovation Institute to answer the first of the two major questions that we have in this course. That is specifically, what is additive manufacturing? We have to recognize that additive manufacturing is not a single thing but actually represents a set of processes and underlying technologies, each of which applies in different contexts. Now, I'm happy to say that I'm joined here by two important collaborators. The first is Amy Elliot, an engineer from Oakridge National Laboratories, who specializes in additive manufacturing, and Kevin Collier the factory innovation manager here at America Makes. We're going to rely on Amy and Kevin to share their expertise about the applications, advantages and disadvantages of each of the additive manufacturing technologies that we look at. Now, the American Society for Testing and Materials, otherwise known as ASTM defines seven key processes that we can think of under which the entire technology architecture for additive manufacturing actually exists. We're going to take a look at this as part of a framework. Let's have a look now. The first of the process we're going to look at is vat photopolymerization. That's a process in which liquid photopolymer or liquid plastic, if you will, in a vat is selectively cured, normally using UV light. The technology that we're going to specifically look at there is stereolithography or SLA. Our second process will be material jetting. That's a process in which droplets of build material are selectively deposited on a build platform and then frequently cured once again using ultraviolet light. Our third process is material extrusion. That's a common additive manufacturing process in which material is selectively dispensed through a heated nozzle. We'll look at this in the context of two related technologies, fused deposition modeling and fused filament fabrication. Our fourth process is powder bed fusion. That's a process in which thermal energy, think of lasers is used to fuse material either metal or plastics in a powder bed. We'll look at two technologies here, the first being electron beam melting, and the second being selective laser centering. Our fifth process is binder jetting. This is a process in which powders are bound together not using heat or UV light, but rather using a type of glue that holds it together until additional processing can be performed. Here we'll look at binder jetting as a general class of technologies. Our sixth process is sheet lamination. This is an older additive manufacturing technology in which sheets of material be they paper, plastic or metal are bonded together to form an object. We're going to pay special attention here to ultrasonic consolidation. Our last process is directed energy deposition. This is a process by which thermal energy think of a laser, is used to fuse material as it's being deposited. Rather than having that same laser be applied to a bed of powder that already exists. Over the next eight segments we'll discuss each of these technologies and processes in some depth with the goal of positioning you to have the same conversation with others in your organization. Let's get started.