POLYMERIC composites, RAPID prototyping, RAPID tooling, SINTERING, LASERS, and HUAZHONG University of Science & Technology (Beijing, China)
Rapid prototyping (RP) and tooling (RT) are the technologies for quickly fabricating functional components and tooling inserts directly from CAD data by selectively adding material layer by layer. In this paper, multiphase polymeric materials for RP and RT technologies and their applications, which are developed by the Rapid Manufacturing (RM) Center of Huazhong University of Science and Technology (HUST) in China, were introduced. Selective laser sintering (SLS) is a powder-based RP process. Multi-types of multiphase polymer materials for SLS process were successfully developed in the RM center, and the SLS components were formed from these materials by using the commercial SLS machines HRPS series for various applications. High impact polystyrene (HIPS)/wax blend SLS parts were used as lost patterns for the investment casting process to make complex metal parts rapidly; nylon-12/organically modified rectorite and nylon-12/nanosilica composite powders were used to fabricate functional parts, which showed higher thermal and mechanical properties than neat nylon-12 SLS parts. As a RT application, Fe/epoxy composite tooling inserts were rapidly fabricated by SLS and post-processing. Stereolithography (SLA) uses photocurable resins to rapidly manufacture components with high accuracy and mechanical properties. A freeradical and cationic mixed-type radiation curable composite resin was also successfully developed, and SLA parts without obvious distortion were built on the SLA machines HRPL series from this hybrid resin, successfully and efficiently. [ABSTRACT FROM AUTHOR]
Dong Guo, Long-tu Li, Kenji, Kai Cai, Kenji, Zhi-lun Gui, Kenji, and Ce-wen Nan, Kenji
Journal of the American Ceramic Society; Jan2004, Vol. 87 Issue 1, p17-22, 6p
PIEZOELECTRIC ceramics, LASERS, SINTERING, PIEZOELECTRICITY, CERAMICS, and RAPID prototyping
This article presents a new lost mold rapid prototyping method which combines selective laser sintering (SLS) and gelcasting techniques for fabricating piezoelectric ceramics. SLS was used to fabricate sacrificial molds of the desired structure of the ceramic part. Then aqueous PZT (lead zirconate titanate) suspension was cast in the mold and solidified in situ through formation of a three-dimensional network gel. Because the polymer mold can be easily removed at the initial stage of sintering and the gelcast PZT body has a high green strength, the desired geometry of the PZT part can be completely retained after sintering of the ceramics. Complex-shaped PZT parts were successfully fabricated after using concentrated PZT suspension with low viscosity. Densities and electrical properties, such as the d[sub 33], the relative permittivity ε, the dielectric loss tgδ and the electromechanical coupling factor K[sub p] of the gelcast PZT parts were also compared with those of the die-pressed PZT samples. The results indicated that the gelforming process did not deteriorate the electrical properties of the samples, if proper dispersant was selected in developing concentrated ceramic slurry. [ABSTRACT FROM AUTHOR]
RAPID prototyping, PROTOTYPES, SINTERING, LASERS, and INDUSTRIAL design
The article focuses on the technologies and processes used in the rapid prototyping (RP) system and offers steps involved in selecting the right RP. It discusses the scanning laser autotype (SLA) systems and the Selective Laser Sintering process which are part of the RP systems. It is stated that while choosing the right RP system, it is important to select a reputable service provider which offers a breadth of RP solutions.
RAPID prototyping, PHOTOPOLYMERS, SINTERING, LASERS, and ELECTRON beam furnaces
The article discusses tools and methods to enhance rapid prototyping. A description on how to accurately cure layers of liquid ultraviolet (UV)-curable photo-polymer resin using stereolithography is provided. A discussion of the selective laser sintering (SLS) process is given. Other competing technologies for fast and easy model building are discussed, including fused deposition modeling, electron beam melting, three-dimensional (3D) printing and laminated object manufacturing.