Potassium dihydrogen phosphate (KDP) is a non-linear optical and water-soluble crystal. However, since KDP is brittle material, it takes a large cost to obtain the surface roughness required in generating harmonics. Therefore, a new polishing method using YAG laser beam is developed and verified the method by experiments in our research work. The method developed in this paper is as follows. A YAG laser beam is focused at an edge of an end face of a single crystal in a saturated solution. The laser beam is scanned along the edge of the end surface. It is possible to polish the scanned surface by the solution of the crystal and the other portions are not removed in a saturated solution. In this paper, the surface of the crystal polished by our laser beam scanning method was compared with that polished by sandpapers. The surface polished by laser beam scanning is smoother than that polished by sandpapers when the both surface roughness were same. The crystallinity of both crystals after polishing were same degree by X-ray diffraction analysis. The second harmonic generation were performed using KDP crystals before polishing, after laser beam polishing and after sandpaper polishing. The intensity of the light from the crystal by the laser beam polishing was the best of these three crystals.
The purpose of this study was to investigate factors affecting the variation of friction coefficient in intermittent cutting of aluminum alloy A5052 with non-hydrogenated diamond-like carbon (DLC) coated tool. The orthogonal intermittent cutting tests using workpieces that have different length of cutting parts (L1) and different clearance of cutting parts (L2) were conducted. Additionally, the orthogonal intermittent cutting tests under O2, N2 and air blow were conducted. There was an area where no aluminum adhered on the tool rake face after all tests in which friction coefficient decreased. It was cleared that the decrease of friction coefficient in the latter stage of the intermittent cutting depended on the actual cutting distance. Much aluminum adhered on the tool after the test under O2 blow. On the other hand, little aluminum adhered and the friction coefficient decreased in the test under N2 and air blow.
In this study, we have proposed a new method to manufacture high pressure composite vessels for hydrogen storage. With the new method, a new filament winding machine which has multiple delivery eyes is used. By laminating composite layers with a lot of delivery eyes at once, the manufacturing time decreases significantly. To eliminate the trouble of tying ends of a lot of fiber bundles which has been a problem in this method, we have added layers for continuous changing the lamination angle in a winding pattern. To evaluate the effect of above layers on the strength of the vessel, we manufactured prototype composite vessels using the above mentioned method with different conditions, and compared with conventional vessels. By adding layers for changing the lamination angle, it became possible to laminate all layers of a vessel continuously. Furthermore, by changing the lamination angle to decrease the gaps between fiber bundles in the layers, the experimental-by-ideal strength ratio improved 21%, and the material usage efficiency improved 29%.
This paper describes the influence of Na2SO4 electrolyzed oxidizing water (It abbreviates as EO water) on copper iron alloy for lead frame after heating processing. First, the etching characteristics of Na2SO4 EO water against the test pieces surface of the heating processing was clarified using chemicals for comparative immersion experiments. The comparative study showed that as for the etching efficiency, Na2SO4 EO water was superior and the influence to exert on the chemical composition in the test piece surface was small, compared with H2SO4 solution. Also, it puts on Na2SO4 EO water uniformly to the copper iron alloy surface after oxidation layer removal, too, by the etching. Next, by the observation using SEM image, the influence of Na2SO4 EO water on the surface shape of copper iron alloy for lead frame was clarified. The results indicated that when using Na2SO4 EO water, little occurrence of alien substance occurs and the surface becomes smooth than H2SO4 solution. Lastly, as for the test piece after heating processing, it did the surface oxidation layer removal experiment by the immersion. The results show that Na2SO4 EO water can remove the surface oxidation layer of the test pieces more efficiently compared with H2SO4 solution.
Pre-hardened steel of 40HRC is normally used in plastic mold. Because there is no need to adjust dimensional change after heat treatment. However, pre-hardened steel over 50HRC is not common due to poor machinability. For improving their machinability, TiAlN or TiN coated cutting tools after cutting several types of 60HRC hardened cold work tool steel were investigated through SEM, EPMA, and TEM. The final aim is to realize pre-hardened steel of 60HRC. The results showed the following : First, flank wear was reduced by decreasing primary carbides of steel. Second, there were plastic deformation areas of TiN coating after cutting all types of steel. Third, the plastic deformation and chipping of cutting tools were prevented by Al based oxide and MnS made from the steel as protective film. Finally, Al based oxide could be used in a wide temperature range. Moreover, MnS inclusion prevented deposition of Fe on the cutting tools during the cutting of steel. These results suggest that it is possible to create 60HRC hardened cold work tool steel of good machinability by decreasing primary carbides of steel and using Al based oxide and MnS made from the steel as protective film.
This paper presents an experimental study on damping characteristics of a square pipe packed with steel balls and silicon oil. The effects of steel ball diameter, total mass of steel balls, and viscosity of silicon oil on the vibration damping characteristic and sound characteristic are examined using impulse excitation method. It is shown that the damping characteristics are strongly affected by the diameter of steel ball and the viscosity of silicon oil, and that the sound characteristic is significantly improved by packing the pipe with steel balls and silicon oil. It is also shown that the damping capacity becomes the maximum at a certain value of the parameter, μ/d2ρP, where μ is the liquid viscosity, d is the ball diameter, and ρP is the ball density.
We propose a 3D-shape measurement technique of a rough surface using speckle interferograms captured under ramdom changes of optical path differences. Amounts of the phase shifts between captured interferograms are calculated through Max & Min light intensities searchings at two different pixels in frames and twin normalizations of their intensity changes. The calculated phase shifts which involve random changes over 2π are used to extract phase distribution of a speckle interferogram. After capturing 175 specklegrams which consist of 25 specklegrams at wavelengths of around 778.201nm, 778.217nm, 778.258nm 778.366nm, 778.623nm, 779.151nm and 780.260nm, phase distributions are extracted regarding the first captured interferogram in each wavelength. These distributions normally involve uncertain offsets due to random shifts. After canceling these offsets with the phase data at a base-height pixel selected arbitrarily, the ratios of phase change against wavelength change are extracted at all the pixels. 3D shape is calculated from the extracted ratios.
In this paper, we discuss efforts to enhance customer value by reducing customers' life cycle costs (LCC) of construction and mining equipment. Though it is necessary to quantitatively grasp the LCC for the reduction of it, many uncertainties included in LCC of construction and mining equipment have made it difficult. In order to solve this problem, the uncertainties were classified into two types. Then we proposed countermeasures required for three types and showed their effectiveness. The first is to quantitatively measure machine operation data by telematics services and to visualize how it is used. The second is to take countermeasures by the telematics information to maintain the machine conditions. By carrying out the first and second countermeasures by telematics services, accurate simulations of future LCC of these two types of uncertainties become possible. The third is fundamental removal of factors that are accidental and uncontrollable. This was demonstrated by the reduction of accident risks of the autonomous haulage system for mining. By combining the three countermeasures, uncertainties in LCC can be reduced. That makes appropriate LCC reduction countermeasures possible and creates customer value, which is obtaining benefits with less cost.