What is the disadvantage of sheet lamination process?

Sheet lamination: Ultrasonic consolidation

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- Hi, welcome back. In this segment, we're going to look at a process called sheet lamination and in particular, two technologies, laminated object manufacturing, which we'll get an overview in just a little bit, and then we're going to go deep on something called ultrasonic consolidation. Now, we're fortunate to have Amy with us who's going to help us understand some of the applications, the advantages and disadvantages of these technologies. Sheet lamination is just what it sounds like. In essence, we're taking sheets of material. In this case, I've got a piece of paper, but it could just as easily be plastic or more recently, metals. And we're binding them together one layer on top of the other as we see in most additive processes. We could do that using some sort of a glue or other binder or we could actually weld them together using some type of manufacturing process. Now, sheet lamination is one of the older additive technologies. Traditionally, we find use, at least in the early days, in architectural modeling. So if we go back to a day when architects wanted to be able to show a client exactly what that building's going to look like, they would use a sheet lamination process using paper to build that up layer by layer. More recently, we shifted into polymers and into metals. We're going to take a look at that process using metals in the form of a video. So this video comes from our friends at Oak Ridge National Lab. We're looking at sheet lamination using metals. An advantage of this process is that it can be done in the open air. And here, we're seeing a sheet of metal already being milled out. - [Amy] So you can see we have this dispenser that's dispensing the sheets of metal. - [Mark] Coming off a roll at the top. And in a moment, we're going to go around back and take a look at what that looks like. - [Amy] Since this process is actually at a room temperature we can actually embed wires. It's not going to damage the wires. After every layer, though, we do have to come back and cut that sheet out with a milling head. - [Mark] All right, so here's the back side. We're seeing that roll come off and that's a crimping process to cut off the sheet, so that we can begin our milling process one more time. Over and over and over. - [Amy] So this welding head actually rolls over the sheets and vibrates such that each sheet gets welded to the other one. So it kind of shakes them together and friction welds them together. - [Mark] So they become a solid mass. - [Amy] Exactly. So you can do internal structures with this process. You can do channels. You can do dissimilar materials. You can see here we started with maybe a copper material and we finished up with maybe an aluminum or stainless steel. - [Mark] So we've already machined internal geometries here and then covered them with subsequent layers of material, ending with a solid mass. - [Amy] Exactly. - So can you help us understand what some of the key application areas, other than maybe architecture, are for this kind of technology? - This is a really great technology for applications where you need to join dissimilar materials. So here's an example part where we've joined aluminum with copper. Now, these two materials have very different melting temperatures. So making this type of product with two different materials is really almost impossible with any other technology. Another great application is applications where you need to actually embed wires or circuitry or electronics because this process is done at a room temperature, so you're not going to damage any components. - So it's not going to melt them if-- - Exactly. - Okay, terrific. - So any sensitive components can be put into this process. - I want to zoom in on the edges of this thing because even though it's layer after layer of material, I don't see a lot of stratification in here. - Exactly, so it's actually pretty good welding quality. You won't be able to see, like, flakes of the layers because we have welded that together and then machined it smooth. - Okay, now, in contrast, I look at this part, which is made of plastic, and I do see layers here. Could you tell something about how this piece is made? - Sure, so this is made in the same fashion. We're laying down layers of clear plastic and then we're actually cutting those contours with a laser and then we're removing that excess later in a manual process. So yeah, so this is the same technology, just sheets of plastic material. - Okay, terrific. Any big disadvantages for this technology? - A big disadvantage would be that we can't do super complex shapes, just because the machining just adds another level of limitation to what complexity that we can achieve. Also, the weld quality is sort of under question. We generally get good quality, but that's still something that researchers are working on. - Okay, so in essence, we've got an older additive technology, roots in architecture, but we're transitioning into metals, particularly around embedded electronics that's good for us because at room temperature, we don't damage the electronics through the high heat of maybe some of the other processes. But maybe some suspicions about weld quality, maybe some challenges around the complexity of the parts that we're actually manufacturing.