Metal additive manufacturing (AM) technologies are classified into two groups according to the consolidation mechanisms and densification degrees of the as-built parts. Densified parts are obtained via a single-step process such as powder bed fusion, directed energy deposition, and sheet lamination AM technologies. Conversely, green bodies are consolidated with the aid of binder phases in multi-step processes such as binder jetting and material extrusion AM. Green-body part shapes are sustained by binder phases, which are removed for the debinding process. Chemical and/or thermal debinding processes are usually devised to enhance debinding kinetics. The pathways to final densification of the green parts are sintering and/or molten metal infiltration. With respect to innovation types, the multistep metal AM process allows conventional powder metallurgy manufacturing to be innovated continuously. Eliminating cost/time-consuming molds, enlarged 3D design freedom, and wide material selectivity create opportunities for the industrial adoption of multi-step AM technologies. In addition, knowledge of powders and powder metallurgy fuel advances of multi-step AM technologies. In the present study, multi-step AM technologies are briefly introduced from the viewpoint of the entire manufacturing lifecycle.
An AVL research engine, type 520, is modified to adapt to the 3.5L four-valve SI engine. With these given engine configurations, a test rig is constructed which allows easy changing of the different pistons and engine heads with a motoring capacity up to 3500 rpm. Nearly complete optical access to the inside of the cylinder is obtained by installing a transparent quartz cylinder on an AVL single cylinder engine. To avoid lubrication and to minimize scratches in the quartz cylinder the piston rings are made of Rulon-LD. With this experimental engine, researches for the in-cylinder flow characteristics by changing the induction system have been carried out using the laser based flow diagnostic techniques. In accordance with the previous result, it is evident that larger sized particles would be required in order to observe the flow characteristics of interest. The flow visualization taken with microballoon particles shows significant improvement. This provide detailed information.
The purpose of this study is to improve a process of the automatic manufacturing system for producing a phosphor bronze wire developed the previous study. For this purpose, the authors have improved the manufacturing process, such as wire tension control, discoloration, winding and the control appears as a problem when the automatic manufacturing system applied to the field. Also, performance tests for the developed system such as the straightness, tensile strength, hardness, diameter deviation, discoloration have been performed. As a result, we could product the 0.35mm of phosphor bronze wire with continuous processes. The performance of the prototype system satisfies all the objects of this study.
In this paper, patent trend on the rapid prototyping technologies is analyzed. The results show that USA has the most patents, the largest citations, and the highest CPP(Citations Per Patent) at the rapid prototyping field, and that 3D SYSTEM in USA has the most patent filings among the whole world company. and STRATASYS in USA is ranked with the highest CPP representing a technology impact in that field. It is shown that molding or bonding technology of plastic is occupied 31% by International Patent Classification Index(IPC).