Layer manufacturing

Recent new techniques have been developed to gradually build up a component by adding more material in solid powder form followed by sintering or soldering, in fluid form followed by solidification, or in gaseous form followed by chemical reactions or physical deposition. These techniques mosdy work on the so-called layer manufacturing principle. A close control of the layer-based addition process is therefore required to achieve the final dimensions, accuracy and surface finishes. 

The laminated floor covering has three layers, with top and bottom layers manufactured according to the above formulation. The middle layer is composed of a carbon fiber-glass fiber (50/50) layer which is sandwiched between the two PVC layers. The resistivity of material is 7x10 Q. 

Conventional manufacturing and production processes do not generally lend themselves to mimicking complex architectures found in nature. Layered manufacturing methodology is a very effective way of exploring 2D layered mechanisms, common in the natural world. Artificial muscles and smart soft composite prototypes can be produced cheaply and efficiently (Weiss et al., 1997 Ahn et al., 2012), yetpose limitations in the realization of more complex 3D mechanisms that utilize fiber orientation. 

D printing Layered manufacturing Selective laser sintering Stereolithography... 

From the beginning, and still today, layer manufacturing techniques are mainly used for fast and cost-efficient production of prototype parts for concept studies (rapid prototyping). But, since applicable materials and reliable machinery have been developed recently. 

Laser Beam Machining, Fig. 6 Micromechanical components with moveable parts generated by laser-based layer manufacturing (microstereolidiography)... 

Additive methods processes also called Additive or Layered Manufacturing or Rapid Prototyping that lead to the faMcation of the prototype through the deposition of portions (normally layers) of the object. The power of these methods is the potential to manufacture shapes with virtually no limits to complexity (Chua et al. 2003). 

Stereolithography (SL) is one type of layer-by-layer manufacturing process, based on photopolymerization of a photocurable resin, that was first reported in 1981 by teams from... 

Rapid protot5rping processes are layered manufacturing techniques wherein an article, e.g., metal casting mold or a prototype part, is progressively made in a series of sequentially built-up layers (19). 

Additive manufacturing, also known as rapid manufacturing, is a powerful tool that uses layer-by-layer manufacturing to build a part by polymer addition. Fabrication is obtained directly from the three-dimensional (3D) computer-aided design model, sliced into layers that are printed one upon the other (Petrovic, 2011). Additive manufacturing... 

Petrovic, V., Vincente Haro Gonzalez, J., Jorda Ferrando, O., Delgado Gordillo, J., Ramon Blasco Puchades, J., Portoles Grinan, L., 2011. Additive layered manufacturing sectors of industrial application shown through case studies. Int. J. Production Res. 49 (4), 1061-1079. 

The MFEs are coated particles similar to TRISO fuel with the outer diameters of about 2 mm. They consist of 1.5-1.64 mm diameter uranium dioxide spherical kernels coated with 3 ceramic layers. The inner layer, called a buffer layer, is made of 0.09 mm thick porous pyrolythic graphite (PyC) with the density of 1 g/cm, providing space for gaseous fission products. The second layer is made of 0.02 mm thick dense (1.8 g/cm ) PyC, and the outer layer is 0.07-0.1 mm thick corrosion resistant silicon carbide (SiC). The fourth, outer PyC layer is assumed to be absent. SiC protection layers, manufactured by chemical vapour deposition (CVD) method, create resistance of graphite components against water and steam at high temperatures. Small fuel elements are able to confine fission products indefinitely at temperatures below 1600°C. 

Ahn D, Kim H, Lee S (2009b) Surface roughness prediction using measured data and interpolation un layered manufacturing. J Mater Process Technol 209(2) 664—671. doi 10.1016/J.Jmatprotec. 2008.02.050... 

Coddet P, Liao HL, Coddet C (2014) A review on high power SOFC electrolyte layer manufacturing using thermal spray and physical vapour deposition technologies. Adv Manufact 2 212-221... 

This chapter is organized in five sections. The first reviews the various lasers used in laser micromachining and the principles of interaction of laser light with matter. The second section gives examples of laser ablation of polymers and their applications. Two other sections are devoted to surface modification and generative laser processes based on layered manufacturing. Finally, a number of other laser-based processes are presented, before concluding. 

Laser-based generative processes such as stereolithography and selective laser sintering are part of a group of techniques commonly known as layered manufacturing . These are rapid prototyping techniques that build up a 3D object (or physical model) layer by layer. They are used in fields like mechanical engineering, and more recently in medicine and health care, as they are fast and cost effective techniques for the manufacture of 3D parts. 

Krulh, J.P., Levy, G., Klocke, F., and Childs, T.H.C. (2007) Consolidation phenomena in laser and powder-bed-based layered manufacturing. Ann. CIRP, 56, 730-759. 

Both negative- and positive-working ED photoresists can be used in primary imaging applications, the former being used mainly as an etch resist in inner-layer manufacture and the latter mainly for outer-layer imaging, where protection of plated through holes is necessary. 

The current laser micro-nanofabrication systems stem from the conventional laser prototyping method [6]. Figure 7a illustrates its concept, and for reference, three other layered manufacturing technologies are also shown (Fig. 7b-d) [6]. 

Fig. 7 Illustration of several types of layered manufacturing technologies, a Laser rapid prototyping using photopolymerizable resin, b powder sintering, c ink injecting and writing and d resin squeezing and writing...

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