Advanced Materials Research Vols. 291-294

Abstract: In this work, in-mold rheology curves were generated by injection molding machine and the effects of feedstock and mold dimension on in-mold rheology curve were studied. The rheology within mold in µMIM process depends on the shape and/or size of cavity and process conditions rather than intrinsic viscosity of feedstock. The optimum injection speed was determined in region of Newtonian flow of in-mold rheology curve. The dimensional deviation was below about 5 µm in the micro part injected with the optimum speed.

Abstract: The micro parts were fabricated by electroforming process of Fe-Ni alloy. Reaction mechanism of Fe-Ni alloy electrodeposition process was investigated using rotating disk electrode. To clarify the rate determining step, the activation energies of iron and nickel elements were calculated from the Arrhenius plot in the temperature range of 308K~328K. The reaction rate of iron in electrodeposition of Fe-Ni alloy was controlled by chemical reaction at temperature range of 308K~318K, while at range of 318K~328K, it was controlled by mass transport. The reaction rate of nickel was controlled by chemical reaction at 308K~318K and by a mixed mechanism of chemical reaction and mass transfer at 318K~328K. For alloy electroforming of micro gears and a mold for powder injection molding, the mandrels of micro gear (1.7mm in diameter and 600 μm in height) and micro mold (550 μm in diameter and 600 μm in height) were prepared by UV-lithography using SU-8 photoresist. Subsequently, Fe-Ni alloy micro gear mold were electroformed with high hardness (490 Hv) and very good surface roughness (Ra 37.5 nm).

Abstract: The aim of this research is to propose and develop the in-process monitoring system of the tool wear for the carbon steel (S45C) in CNC turning process by utilizing the multi-sensor which are the force sensor, the sound sensor, the accelerometer sensor and the acoustic emission sensor. The progress of the tool wear results in the larger cutting force, the higher amplitude of the acceleration signal, and the higher power spectrum densities of sound and acoustic emission signals. Hence, their signals have been integrated via the neural network with the back propagation technique to monitor the tool wear. The experimentally obtained results showed that the in-process monitoring system proposed and developed in this research can be effectively used to estimate the tool wear level with the higher accuracy and reliability.

Abstract: High performance simulation has great prospect of application in the fields of Materials Science and Engineering. In high performance simulation, high performance computers are used to improve the performance of simulation. As one of the simulation standards, HLA simulation was greatly applied in computer simulation. In HLA simulation domain, many RTIs are designed to support the simulation in LAN/WAN environment. Because of the general TCP/UDP communication mechanism, high simulation performance can’t be achieved by these software on high performance computer. To improve the simulation performance, a customized RTI software for high performance computer and PC hybrid environment is designed. By using of partially hierarchical design on functional distributed architecture, large scale simulation can be supported. An adaptive communication mechanism is proposed, which can adapt communication between different RTI components to shared memory, Infiniband and Ethernet automatically, thus can greatly improve communication performance. In addition, this paper explains the related design in this customized RTI.

Abstract: Three traditional color separation methods such as automatic color separation of fabric CAD, self-defined primary color separation and spot color separation are analyzed by comparison , the advantages and disadvantages of color separation based on cluster analysis are discussed by tests . On this basis, an improved fabric color separation method is put forward based on genetic fuzzy clustering algorithm, and the experimental results show that the fidelity of fabric patterns after color separation using this improved method is superior to that after color separation using traditional color separation method.

Abstract: Aiming at key problem of sustainable development of modern manufacturing enterprise how to intelligent reuse and share manufacturing resource of enterprise. Command intelligent multi-agent technology was proposed. in this method, in order to smart reuse and share manufacturing resource of enterprise , reconfigurable modules(resource carrier, command agent)play a control role, when these modules were reconfigured, it communicated with agent of manufacturing resource, then the relevant sub-agent of manufacturing resource was reconfigured based on command; so these manufacturing resource were reused and shared in new modules. Then, Command intelligent multi-agent system and organization were discussed; finally, a case that organization command agent was simple discussed.

Abstract: A model on non-sinusoidal oscillation of continuous casting mould was established to study the pressure in flux channel. The effects of oscillation parameters on the pressure in flux channel were researched. The non-sinusoidal oscillation parameters were optimized. When the casting speed is 1.8 m·min^-1, the optimized oscillation parameters are: non-sinusoidal factor (α) is 0.198, oscillation amplitude (s) is ±4mm and oscillation frequency (f) is 165min^-1. When the casting speed is 2.0 m·min^-1, the optimized oscillation parameters are: α is 0.186, s is ±4.5mm and f is 155min^-1. These optimized oscillation parameters are proved applicable in practice.

Abstract: This paper presents a new approach to precision cropping with radial forging, it skillfully utilizes the stress and strain concentration effect of the prefabricated V-shaped notch and the principle of the radial-forging machine to achieve the regular fracture of metal bar. The basic working principle of the new radial-forging cropping method is discussed in detail. Moreover, the distribution of the radial displacement loads is discussed in detail, and the loading rules are clearly explained under the conditions of the single cropping die, two cropping dies, three cropping dies and four cropping dies, as well as the radial-forging loading sequence. The model and equation of the movement with the radial-forging are established, the feasibility analysis of the radial-forging cropping method is carried out, which is in agreement with the experimental results.

Abstract: This paper presents a new method to fabricate tungsten microelectrode in a single pulse electrical discharge. The electrode material, diameter and polarity affect the shape of probe. The 80μm diameter tungsten wire between 500 and 600μF capacitance can be fabricated in 1μm tungsten electrode probe tip. The experiment use different material such as W, Cu and Mo. Finally, in the condition of “negative pole machining”, only tungsten can be used to make probe. It can greatly shorten the microelectrode fabrication time and effectively improve the reliability of the microelectrode and can fabricate a nanometer level tip in general electrical discharge machining (EDM) machine tool not add any other apparatus. The fabricated microelectrode can be used as a probe for scanner and measurement devices.

Abstract: This paper studies the electrochemical machining on the surface of nickel-based alloys with a tubular electrode and analyses the effect of electric field distribution and current distribution to the shape of concave holes during the processing. It is concluded that the maximum distance between the positive and negative poles in the reaction of electrochemical machining. It is analyzed that order of electrochemical machining surface holes in the direction of hole radius and hole depth and the variation laws of reaction speed.