Advanced Materials Research Vol. 939

Abstract: We consider the parts screwing problems, which of automatic assembly robotic screwdrivers system required precisely depth and tilt-angle at each insertion point. However, commonly computer vision inspection tools which obtain tilt-angle on clamping printed circuit board is a challenging problem. Further, even if given a depth senor, that still to consider inspection target size. Thus, we present an approach for screwing angle measurement of printed circuit board assembly in Consumer electronics production lines. The methods involved using 2D-Depth sensor to identify screwing angle, and measuring depth information near the hole of printed circuit board. Our method successfully conform to screwdrivers system requirement, tilt angle under three degree and sampling small area target under 10mm^2,which obtains measurement results will be applied to refer on robotic positioning and assembling.

Abstract: Monolayer titanium carbide nitride (TiCN) and multilayer TiCN reinforced titanium (Ti) are coated on the surface of Ti6Al4V alloy by Filtered Arc Deposition System (FADS). Surface chemical composition has been characterized by an X-ray diffraction (XRD). Wear resistance of TiCN coating and TiCN/Ti coating have been detected by hommel tester T1000. Hardness and deformation mechanisms of the multilayer coatings are investigated using depth-sensing indentation comparison with the monolayer TiCN coatings. Focused Ion Beam (FIB) and Transmission Electron Microscopy (TEM) are used to identify the fracture modes of the coatings. The TEM image observations show that the inclined crack is the dominant crack in the monolayer TiCN coating while small bending crack is the dominant crack in the multilayer TiCN/Ti coating. The Ti layer with good ductility could efficiently suppress the crack propagation and absorb more indent energy.

Abstract: The present work is aimed at investigating the effect of speed , slurry concentration and particle size on Inconel-718 coatings on copper subjected to slurry erosion with the help of DOE (design of experiments) tool among which the Taguchi technique is well known. The coatings are subjected to slurry erosive wear tests in 3.5% NaCl solution (35 gms NaCl/ ltr of water) with sand as erodent. On application of analysis of variance, it is found that all three parameters namely speed, sand concentration of the slurry and particle size are significant with speed being the most significant one.

Abstract: Deposition of gallium-doped zinc oxide (GZO) thin films using atmospheric pressure plasma jet (APPJ) system is presented in this work. High quality GZO films were demonstrated: The resistivity of as-deposited film achieves up to ~7×10^-4 ohm-cm, which is comparable to that deposited using vacuum process. Further, the optical transmission with optimized thickness is > 89 % at wavelength of 550 nm. The Hall mobility increased as GZO deposition thickness increase to 300 nm. In order to study thermal stability of GZO thin films, the effect of thermal annealing on the optical and electrical properties was studied. Samples annealed in vacuum and in air showed opposite characteristics: resistivity decrease for vacuum annealing samples and increase for air annealing samples. Carrier reduction mainly attributed to the resistivity increase in air annealing. Mobility increases but carrier concentration decreases when samples were annealed in vacuum: The combined effects resulted in resistivity decrease to half of the prior-annealing values after 500 °C vacuum annealing. The GZO thin films used in capacitive touch sensors were also evaluated. We demonstrated that APPJ-deposited GZO thin films can be successfully applied to touch sensors in our work. These results indicate that our APPJ system can deposit good quality TCO films, which have potential to be applied in optoelectronics field.

Abstract: Cold forging is a highly efficient process to produce components. However, the occurring tribological loads are tremendous. Therefore, complex tribological systems are necessary. They can be influenced by numerous factors. Most important are the tribological loads, which can usually be investigated independently. On the other hand, the contact normal stress and the surface enlargement are coupled in tribometer tests. In order to investigate them independently, a new concept for the Sliding Compression Test is presented and verified. This procedure reveals that both values have an influence on the friction coefficient. However, the influence of the surface enlargement is with about two-thirds higher.

Abstract: As the needs of optical glasses are on the rise, the precision on shape, form, surface qualities and the scaling down of sizes are rising, too. The standards and surface finish of reference mirrors used in measuring appliances are crucial; hence, enhancement of the surface finish is indispensable in manufacturing industries. This paper proposes a self-propelled multi jet polishing technique for ultra precision polishing process in which bladeless Tesla turbine was used as a prime mover. The turbine is characterized by high swirling velocity at the outlet; therefore, high kinetic energy in the course of away from the turbine was used as polishing energy. Simulation of the flow of the field of turbine blades using computational fluid dynamics software (CFD) has also been presented. With a newly designed and manufactured polishing tool, this paper investigates the optimal polishing parameters for surface roughness improvement of crown optical glasses using Taguchis experimental approach; signal-to-nose (S/N) ratio and ANOVA analysis was also carried out to determine the effect of main factors on the surface roughness. Consequently, a 2.5μm size of Al₂O₃ abrasive, 10wt% abrasive concentration, 80rpm of polishing head, 6 numbers of nozzles, 6 kg/cm² of pressure, and 45min. of polishing time have been found to be the optimal parameters. It was observed that about 94.44% improvements on surface roughness; Ra, from 0.360μm to 0.020μm has been achieved using the optimal parameters. In addition to this; angular speed of polishing head, pressure and polishing time were found to have significant effect on surface roughness improvement.

Abstract: In various industrial fields, it is frequently necessary to measure surface roughness in confined spaces such as boreholes and grooves. However, using a small stylus, the surface roughness of a narrow borehole can be directly measured only a few millimeters from its end; alternatively, destructive measurements must be performed. This major disadvantage of conventional stylus-based surface profilometers is mainly due to an inductive pick-up that is connected to the stylus used to detect the surface roughness. In this paper, we propose a novel surface roughness measurement sensor. To make the surface roughness sensor small, we used a stylus with a cylindrical mirror and a lensed fiber instead of a conventional inductive pick-up. The proposed sensor converts the signal obtained by measuring the surface roughness of a borehole into an optical signal, which is transferred outside the borehole by an optical fiber. Experimental results demonstrate that this system has a measurement range of 8 μm and a sensitivity of 19 nm. Surface profiles were measured by the proposed sensor and by a conventional surface profiler and the results were found to be very similar.

Abstract: This paper does some research about the drag reduction mechanism of dolphins soft and adaptive skin in view of bionics. The study shows that dolphin skin is very sensitive to pressure changed by external flow field, and can do a wave-like movement with the uneven pressure, resulting in a traveling wave of the non-smooth surface which reducing frictional resistance on the wall surface in the turbulent flow field. Based on Karman vortex street and momentum theory, we described the relationship between the geometry of traveling wave and the drag reduction efficiency, and with the help of numerical simulations of traveling wave surface using RNG k-ε model and a series of experiments, we get the friction coefficient near the wall boundary, the turbulence intensity, and the distribution of the velocity field. The results show that, compared with smooth surface, the non-smooth surface of traveling wave reduces frictional resistance of the adhesion surface owing to changing the fluid flow state. Moreover, the non-smooth surface of traveling wave shows significant drag reduction effect at the stream velocity about 6 m / s.

Abstract: The paper investigates using a secondary solar concentrator to augment the solar energy density focused by a primary concentrator (a paraboloid dish). The secondary concentrator protects the focal point from cooling by convection from wind, and also would harness all the solar rays reflected by the primary concentrator, resulting in reduced losses due to aberration and other errors in finding the focal point. The intended application is the utilization of solar energy for nonferrous material ablation that could potentially replace or assist industrial lasers

Abstract: As society became more complex, the logistics also increased, demanding for logistics transport vehicles and feeder has increased. Because the self-weight of skate for cargo transport used in this study is heavy, it needs to be weight lightening. However there is a lack of capital and technology not to improve lasting. We conducted FEM studies about weight lightening applying composites on cargo transport skate and the stiffness can be obtained at the same time. However, due to the presence of discontinuities such as holes in the parts. If you are applying composite, Because this causes the degradation of the strength of the material under static and fatigue load induced stress concentration in parts. In order to examine the safety of the cargo transport skate, you must consider the impact of the static strength damage on the stress concentration because of the discontinuous parts. In this study, therefore, the cargo skate was performed to evaluate the structural analysis through the FEM analysis. As a result, it was found that CFRP compared to existing SM45C is superior 25% when considering the characteristics. It indicated the best results in about 30% of the weight lightening.