Layered Manufacturing: Challenges and Opportunities
- PDF / 142,139 Bytes
- 12 Pages / 612 x 792 pts (letter) Page_size
- 99 Downloads / 268 Views
LL1.4.1
Layered Manufacturing: Challenges and Opportunities Khershed P. Cooper Materials Science and Technology Division, Naval Research Laboratory Washington, DC 20375-5343, U.S.A. ABSTRACT Layered Manufacturing (LM) refers to computer-aided manufacturing processes in which parts are made in sequential layers relatively quickly. Parts that are produced by LM can be formed from a wide range of materials such as photosensitive polymers, metals and ceramics in sizes from a centimeter to a few meters with sub-millimeter feature resolutions. LM has found use in diverse areas including biomedical engineering, pharmaceuticals, aerospace, defense, electronics and design engineering. The promise of LM is the capability to make customized complex-shaped functional parts without specialized tooling and without assembly. LM is still a few years away from fully realizing its promise but its potential for manufacturing remains high. A few of the fundamental challenges in materials processing confronting the community are improving the quality of the surface finish, eliminating residual stress, controlling local composition and microstructure, achieving fine feature size and dimensional tolerance and accelerating processing speed. Until these challenges are met, the applicability of LM and its commercialization will be restricted. Sustained scientific activity in LM has advanced over the past decade into many different areas of manufacturing and has enabled exploration of novel processes and development of hybrid processes. The research community of today has the opportunity to shape the future direction of science research to realize the full potential of LM. INTRODUCTION Metallic parts are made by one of several technologies, machined from the bulk, cast in a mold and densified in a HIP. Ceramic parts are made by sintering powder compacts, plastic parts by injection molding. Metallic, ceramic or plastic parts can also be made by layered manufacturing. Layered Manufacturing (LM) refers to building a three-dimensional object layerby-layer, with the architecture of each layer dictated by a CAD drawing. The form is made without support, hence the technology is also known as Solid Freeform Fabrication (SFF). The part could be a solid model designed to serve as a visualization tool in the design of a component, a device or a system. The part could be a functional part, having the same attributes as one made conventionally. The foremost advantage of LM is the ability to make a prototype fairly rapidly, hence the term Rapid Prototyping (RP) is also applied to this technology. In fact, it is in the area of RP that the technology has seen most commercialization. Design engineers and course instructors routinely utilize RP machines for design and instruction. A significant body of research and development work has taken place in LM/SFF/RP over the last 15 years. Today, it can be considered a mature science. Technological maturity is on the horizon. During this period of time, a myriad of techniques has sprouted, driven by the need to fab
Data Loading...
