We have been studying the surface discharge plasma generated by insulating capillary tube as an ablation gun for depositing diamond-like carbon films. It is found in our series of experiments that applying a positive voltage to the gun of the system allows us to fill the entire chamber with plasma. In this study, we propose a new application of the surface discharge technique for plasma nitriding of steel. Nitriding experiments under various temperatures were carried out for SKH51 high speed steel substrate. The hardness of the specimen nitrided at 500°C was the highest in this work. Nitriding depth of the specimen seemed to be more than 40μm. Although X-ray diffraction measurements showed no distinguishable nitride diffraction peaks, the hard X-ray photoelectron spectroscopy (HXPS) measurements suggested the presence of Cr-N and W-N chemical bonds in the nitrided SKH51 steel. Furthermore, so-called “white layer (Fe2-3N)” or damage were not found on the surface of nitrided specimens. It can be concluded that this technique can be one of the most superior techniques for nitriding steel.
The smaller through holes of printed circuit boards (PCBs) are required for the multifunctional information communication devices. This paper describes some experiments on the effect of entry sheet (E/S) on the micro drilling quality of PCB. Especially the effect of the resin painted on E/S on the micro drilling quality was investigated. The effect was examined by performing the micro drilling tests of PCB using the aluminum E/S and the resin painted aluminum E/S. Resin films used were the polyethylene-glycol (PEG) based film and the wax-based film. The effect of the E/S on the position error of hole center was determined by measuring the centripetal action with the non-contact displacement sensor. The effect of the E/S on the hole wall roughness was also determined by examining the relationship between the drill temperature decrease during drilling due to the use of E/S and the adhesion of resin film to the drill. From these experiments, the followings were obtained : (1) On the position error of hole center, the wax-based film is better than the PEG-based film. (2) On the hole wall roughness, the PEG-based film is better than the wax-based film.
CVD diamond film coated carbide tools have been widely used for the non-ferrous metal cutting. The cutting edges of CVD tools have large radii and rough surface due to the microstructure of the polycrystalline diamond particles. Consequently, the precision polishing process is strongly required to obtain CVD tools with sharp edge and polished flank and rake faces. This paper provides an application result of novel UV-polishing process on CVD diamond film. The UV (Ultra-violet ray) irradiation assisted polishing method was developed in our laboratory to achieve the ultra-smooth polished substrates of diamond and SiC. CVD tools with well-polished rake or flank face and sharp cutting edge surface were obtained by the UV-polishing. Four types of cutting tools were prepared by selective UV-polishing on rake or flank faces, and were applied to cutting tests of an aluminum alloy A5052. The UV-polishing of rake and flank face showed superior cutting performance with good surface roughness and low cutting forces. The frictional efficiency between flank and work material surface was decreased by UV-polishing of flank face. These results suggest the high potential of ultra-precision cutting using CVD diamond film coated tools sharpened and polished by the UV-polishing.
A nozzle plate and a cavity base plate are functional parts of an inkjet print head respectively. The thin nozzle plate deformed through heat and its configuration with the cavity base plate. This deformation resulted from a large gap between the linear expansion coefficient of the nozzle plate and the silicon cavity base plate, and brought the deterioration of print quality. In order to solve this problem we replaced the silicon with nickel, and the deformation of the nozzle was reduced. However, it confirmed the new issue of low punch durability of the precision mold when making the nickel cavity base plate by the material transfer processing. To solve this issue, we have decreased the deformation that is applied to the punch for transferring, made the specular surface to the tip of the punch with the grinding process and coated the surface with Diamond Like Carbon(DLC). It has been confirmed that the solutions described above increase the punch durability of the precision mold by 15 times.
A chucking becomes important in the thinning process for electrical device stacking technique and the deposited film planarization for device-multi-layer wiring technique. We developed a pin-type vacuum chuck for high precision machining. It takes refuge from the dust influence to achieve flattening. But it must be considered that the dimpling is caused by wafer deformation due to pin sustainment when a thin wafer is used. In this paper the influence of pin sustainment was analyzed with inhomogeneous process pressure by the fluctuation of surface profile or roughness. In consequence the surface profile fluctuation made the inhomogeneous process load. It was revealed that this affected the dimpling amount.
The present paper deals with experiment and analysis of hole machining of plastic with a sharp knife edge tool. The cutting experiment is conducted at various cutting depths and tool postures, and cutting force components and cut surface profiles are measured in order to investigate mechanics of the cutting process. A simple analytical model is also constructed to better understand the process, where a constant contact pressure and a constant friction coefficient are assumed between the tool and the workpiece. It is confirmed that the experimental and analytical results are in a good agreement, and it shows that the knife-cutting of the plastic (HDPE) can be understood as the simple process where the above assumptions in the analysis are roughly satisfied. From this finding, some suggestions are derived to improve the practical hole machining process for production of automobile fuel tanks made of the plastic.
Effective reuse of parts is necessary to achieve a sustainable society. For that purpose, individual parts should be used with little environmental load. Moreover, because of variety of consumers' preferences and usages, parts should be used with consideration of consumer's characteristics as well as the information on parts. We have developed the part agent system using network agents and RFID technology to manage parts throughout their life cycle. In previous researches, functions of part agents have been developed that supports recall of parts and replacement of parts in consideration of consumers' preference. However, it is also required for part agents to accommodate the state of parts and consumers' characteristics. For that purpose, we developed a function to propose maintenance activities of part using Bayesian Network model. The function calculates the probability of uncertain phenomenon on the part using the model based on the situation surrounding the part such as sensory information and choice of consumers.
This paper presents a novel method on muscular modeling for a digital human. The unique feature is in that it models a muscle at the muscle fascicle level. By modeling a muscle from the internal structure, we aim at improving the visual reality and the efficiency in generating various kinds of muscles, compared with the conventional muscular modeling methods. We applied this method to twenty-five muscles of a human arm. Locating the generated muscles on a bone model and adding the skin model, we simulated the contraction of the muscles. As a result, we confirmed that the visual effect is very satisfactory. Moreover, we applied our GFFD (Generalized Free-Form Deformation) method to the muscular modeling. By automatically transforming the standard muscular model to the individual ones, the time to generate a model has greatly been reduced.