Papers by Author: Shie Chen Yang

Abstract: This study aims to develop a polishing process improvement technology for deep micro-hole knockout hole wall with high aspect ratio, and discuss the optimal polishing parameter combination of abrasive jet machining method and micro-elastic abrasive particles for deep micro-hole knockout hole wall surface. A micro-elastic abrasive process technology was thus developed. The experimental results showed that the micro-elastic abrasive has better grinding effect on the surface roughness of knockout hole wall in length of 300 mm and in inside diameter of ψ2mm in the machining conditions of jet pressure 0.5MPa, volume mixing ratio 2:1 of abrasive particles to additive and vacuum attraction 70 cmHg. It was improved from 2.39 μm Ra (10.74 μm Rmax) to 0.08 μmRa (1.12 μm Rmax), proving the feasibility of micro-elastic abrasive. The surface was improved well, and the process time was shortened greatly.

Abstract: This study investigated the removal improvement of micro burrs of aluminum alloy materials using vibrated abrasive grinding machining. The image processing technology is used to examine and quantify the micro-hole burr profiles. The experimental results show that the micro burr was uniformly removed as the workpiece is fixture with vertical direction. In addition, the burr removal improvements are effectively influenced by the flowing velocity and the vibration energy of abrasive particles. The flowing velocities are dependent on the size and gravity of the abrasives and the vibration energy is determined by the material properties and the hardness of the abrasives.

Abstract: This study investigated the heat transfer characteristics of LED heat sink and the development process technology of graphite heat sink with micro-sized metal powders. Employing the reverse engineering technology, the three-dimension LED heat sink entity was rebuilt and the heat transfer characteristics of LED heat sink were analyzed by CFD numerical simulation and experimental measurement. The numerical results were validated with experimental results and it showed a good agreement. The experimental and simulation results showed that the heat dissipation of LED device could be removed by natural convection effectively. The difference between the maximum temperature and minimum temperature of cooling efficiency was 10°C. For the process technology development of LED graphite heat sink, the graphite powder, metal powder and resin were mixed in specific ratios. The vacuum casting, vacuum pressure casting and rapid die technology were used to manufacture LED graphite heat sink. The experimental results showed that the LED graphite heat sinks developed in this study have advantages of low cost, light weight and attractive appearance as compared with the heat sink of aluminum alloy, and the overall heat transfer capacity is still within acceptable range.

Abstract: To manufacture rapid metal tools, an innovative method based on rapid prototyping and high pressure spraying technologies is proposed in this study. The Sn-Bi metal alloy with low melting point and small thermal shrink was used as the spraying materials. Applying an electric heated device and high pressure boost pump, the melting Sn-Bi Alloy went through a small spray nozzle and atomized into semi-melting minute particles. The atomized particles are then deposited and integrated on the surface of intermediate silicone rubber mold, which is made from the rapid prototyping (RP) system and are successfully used to manufacture rapid wax injection mould. Using the thermal spraying system to manufacture rapid metal mold, the surface quality and the dimensional accuracy of the spray mold is excellent and the fabricated cycle time is short.

Abstract: This paper reports an simulation study to improve the shrinkage of plastic automobile part by optimizing the injection molding parameters using the Taguchi-TOPSIS method. The Reverse Engineering(RE) and rapid prototyping (RP) technique were used to modelling and createing a prototype model of plastic automobile part. Employing the finite element software, MoldFlow Plastic Insight, the effect of injection parameters on the warpage and shrinkage of plastic part were examined carefully. The simulation results show that Taguchi-TOPSIS method provided an outstanding result for the optimization of injection parameters to produce minimum volumetric shrinkage. The injection parameter of melt temperature was the most significant parameter that influences the warpage and volumetric shrinkage for plastic automobile part in this study.

Abstract: This Study Examined the Performance of Abrasive Jet Polishing (ajp) on Skd61 Mold Surfaces Using Wax-coated Sic Abrasives Fabricated by Gas Atomization. Comparison of Surface Quality Achieved Reveals Significant Surface Roughness Reduction by Wax-coated Abrasives. the Wax Coating Not only Covers Most of the Sharp Ends of the Abrasive, Thus Making Smooth the Abrasive Surface; it Being Elastic Also Provides a Cushioning Buffer. these Two Features Contribute to Ameliorate the Direct Impact of Heavy Peening, Thus Preventing Surface Hardening, Superficial Embedment or Deep Scratches. Moreover, Compound Additives Including Water Wax and Water Were Added to the Wax-coated #3000 Sic Abrasives at a Mix Proportion of 500: 1000: 1500 (water Wax: Wax-coated Sic: Water) for Polishing Mold Surfaces of Different Forms. Results Show that the Compound Additives Provide Addition Cushioning Effect and Facilitate the Sliding and Grinding of Abrasives, Resulting in Fine Polishing and Good Surface Quality. the Reflection Property of Micro-groove Was much Enhanced by Ajp Using Wax-coated #3000 Sic Abrasives with the Compound Additives.

Abstract: This study introduces an Abrasive Jet Polishing (AJP) technique using wax-coated abrasive SiC particle to improve the polishing quality of mold surface. The experimental results showed that the surface roughness of EDM machined mold cavity improved by 82% (from 4.23 μmRa to 0.76μmRa) within 90 minutes. Moreover, the parting surface roughness improved by 94.7% (from 1.14μmRa to 0.06μmRa). We show that employing the abrasive jet polishing technique with wax-coated SiC particles, not only the mold surface roughness got a good improvement, but also significantly shorten the polishing time.