Advanced Materials Research Vols. 472-475

Abstract: Large-scale public building (LSPB) is different from general industrial and civil construction, so that some special management methods are attained to handling the complex design environment based on sustainable development theory. Including organization model, design checklist and some interface design management principles are raised in this analysis.

Abstract: Micro-end-milling tools are suitable for machining miniature parts which have complex shape. As the diameters of tools are too small, cannot directly obtain the frequency response functions (FRFs) through impact hammer test at tool tip. This paper employs Receptance Coupling method (RC), couple the tool tip’s FRFs with machine-toolholder system’s FRF, and then get the micro-end-milling tool’s FRF. Establish the coupling model, then finite element and hammer test of the blank gauge tools are used to obtain the coupling transfer functions (TFs). Then analyze the tool tip model by finite element, couple with the machine-toolholder system hammer test result and coupling transfer functions, finally the micro-end-milling tool’s FRFs are obtained. Through the hammer test of blank gauge tool, the effectiveness and feasibility of RC method are verified. The result shows that the RC method is accurate at micro-end-milling tool in steady state milling.

Abstract: The manufacture of micro-nano three-dimensional (3D) probe is a key factor for Micro-nano Coordinating Measuring Machine (Micro-nano CMM) to achieve the precise measurement. This paper proposes a method to fabricate a microball from an optical fibre using a fibre fusion splicer, which is used for Micro-nano CMM to measure miniature workpieces. Utilizing fused optical fibre tapering and choosing proper melting parameters, a microball with diameter of about 100μm and with roundness of less than 2μm could be fabricated. The offset distance between the microball centre and fibre stylus central line due to the gravity effect could be less than 1μm. This approach not only greatly reduces the time for the preparation of the probe, but also extends micro-nano CMM’s capability of measuring miniature workpieces.

Abstract: As demands for the micro array holes in modern industry and the characteristics of micro Electrical Discharge Machining (micro EDM), a new type micro EDM machine tool used to machine micro array holes was designed and manufactured. The machine tool contains following systems: the mechanism system, the control system, the pulse generator system and other auxiliary systems. Each system was studied respectively. Base on a large number of experiments, finally, a sample with 256 array holes was processed by the machine tool. The diameter of single hole is 45µm and precision of the holes is ±1µm. The sample has been successfully applied to R & D test of micro nozzle components

Abstract: Isopropyl alcohol(IPA) is widely used as additive to enhance surface structure and reduce the reflectivity of silicon wafers in alkaline texturing process of mono-crystalline silicon solar cells currently. However, due to its low boiling point and high volatilization, some negative effects are brought into large scale production especially in stability, cost and environment. In this paper, Dipropylene glycol(DPG) which has relative high boiling point was tried to substitute IPA as texturing solution additive. The influences of concentration of DPG and NaOH on etching rate, surface morphology and reflectance spectrum were investigated. It is obviously observed that the silicon is prevented from etching reaction by the existence of DPG. The best weight reflectance of 13.6% is obtained on mono-crystalline silicon surface by an optimized solution of 1 wt% NaOH and 1 wt% DPG at 80°C for 20 minutes. Finally, the influencing mechanism of DPG was also discussed in detail.

Abstract: Based by controlling the orderly changes of friction force between the PZT rotary actuator and supporting faces in mechanical way, a novel kind of inertial piezoelectric rotary actuator is proposed. the dynamic simulation model of the actuator based on karnopp friction model is established, by using matlab software, Four ordered Runge-Kutta calculation method is used to carry out kinematics simulation of the actuator, the curve of driving signal frequency、voltage and dynamic characteristics is conducted, the prototype of rotary actuator is designed and manufactured, the performance of the actuator is tested，The experimental results show that the developed actuator is characterized by large travel (360º) , good resolution (15µrad) , high speed (0.26rad/s) , and work stability. The motion theory and dynamic formulation of the actuator are proved through comparing the results of simulation and experiment.

Abstract: Aimed at the wall slip phenomenon of micro flow, the wall slip boundary condition was added to simulate the process of the micro flow by Polyflow based on the traditional flow analysis method. The effect of the wall slip on the micro flow was verified by comparing the pressure difference data obtained from the simulation with the quoted test data. In addition, based on the Generalized Navier’s slip law, the shear stress and slip coefficient were researched by the numerical simulation analyses to find out the influence of the key factors on the phenomenon of wall slip. The results show that the phenomenon of wall slip is an important factor that cannot be ignored in the micro flow. And only under the high shear stress, the wall slip phenomenon will have an obvious influence on the micro flow. Along with the decrease of the slip coefficient, the wall slip phenomenon becomes more apparent and the micro flow tends to be stable.

Abstract: In practical industrial processing, in order to make the tiny functional devices assembly accuracy as high as possible, which raises an very high requirement for surface quality of micro workpiece. Some of the important factors in controlling the surface quality with the level of the trajectories and forces of the blade across on the workpiece have a great relationship. This paper presents generalized mathematical models of the trochoid and forces combined with the helix cutter geometry used in the industry. And then from both of these aspects analytical laws in-depth of the trochoidal curves and micro-cutting forces variation. It will be of great reference value for the study of micro-milling mechanism.

Abstract: Electrode wear has a great adverse effect on the accuracy of Micro Electrical Discharge Machining (Micro-EDM) and impedes the improvement of Micro-EDM. In this study the distribution of electric field and current density was analyzed exhaustively in order to explore the generating mechanisms of rod electrode wear by finite element analysis and experiment. Experimental results indicated that corner wear occurred first, followed by side wear resulted from skin effect and debris in Micro-EDM, which was significant in enhancing the accuracy of machining.

Abstract: The method of high-energy short pulse laser etching underwater based on thermal - mechanical effect was put forward. In the experiment system with mask and salt solution , heat affected zone was visible decrease and the image of mask was micro-copied at the workpiece surface. Owing to the photochemical reaction and thermal-mechanical coupling effect, uniform line width of 120μm can be obtained.