Applied Mechanics and Materials Vols. 271-272

Abstract: The poor electric conductivity of polycrystalline diamond (PCD) makes it difficult to machine with the conventional EDM process. Inappropriate selection of parameters of the power generator and the servo system leads to unstable working condition and low material removal rate. This paper introduces a method to find optimal parameters in the Electrical Discharge Grinding (EDG) of PCD materials with Taguchi method. The theory and detailed procedures are presented, experimental results are analyzed. The optimized configuration was validated through confirmation tests.

Abstract: Polycrystalline Diamond (PCD) is one of the popular materials in industry because of its superior mechanical properties. With the hardness of up to 8000HV and the thermal conductivity of 360 W/mk, PCD can be used to machine hard-to-machine materials. This paper introduces the statistical analysis of cutting forces in the milling of Titanium alloys with small PCD tools. Nine customized PCD tools with different tool geometries were fabricated by changing the front angle, clearance angle and cutting edge angle. Cutting experiments were carried out and cutting forces were recorded with a DAQ system. Through statistical analysis it was found that clearance angle affected cutting forces more significantly than the other parameters

Abstract: Mo/NdFeB/Mo thin flms were deposited by dc-magnetron sputtering onto Si substrates, then were annealed at 650 °C for 30 min. Nanostructured Mo/NdFeB/Mo films were successfully obtained with the magnetic easy axis of NdFeB perpendicular to the film plane. It was found that the c-axis orientation depends on the NdFeB sputter power. Good c-axis orientation was obtained at 40W NdFeB sputter power. Meanwhile, Mo layer can not only induce the c-axis orientation of NdFeB, but also improve the crystallization of NdFeB grains.

Abstract: In this work, a SiON film with 25.78% nitrogen contents in film composition was deposited by RF magnetron sputtering. Micro SiON cantilevers were fabricated using MEMS sacrificial layer technology for tests. The micro-cantilever bending tests were done with the help of nanomechanical test system to characterize the Young’s modulus of the SiON. The results showed that the Young’s modulus of the SiON was 256 GPa. Because cantilevers can release the residual stress of the SiON film, the Young’s modulus we gained was more accurate than that early gained by other measuring methods.

Abstract: Anglicizing the superalloy mechanical and cutting characteristics, and according to the oil-stone grinding characteristics, choose the current commonly abrasives in the domestic. Processing performance test of inconel 718 deep-hole honing is carried out. The comparison test results show that the grinding performance of ceramic corundum is better than other oilstones at test condition. Grinding characteristics of ceramic corundum is carried on, study show that the size of ceramic alumina grits range from 0.067 to 0.005 μm, The grinding passivated tiny grains of ceramic corundum oil-stone broken and fall off timely, which is beneficial to oil-stones, self-sharpness. The excellent performance of ceramic corundumcan self-sharpening can improves the efficiency of honing effectively.

Abstract: Introducing an gasbag made of novel textile reinforced composite, investigating the tensile properties of this composite through comparison with different directions and speeds tensile test. The research indicates that this composite has preferable tensile properties, and the tensile properties are the same between transverse and longitudinal direction. The tensile fracture is brittle fracture. This result supplies necessary base for application of this new type textile reinforced composite.

Abstract: Titanium dioxide(TiO2) nanotube film electrodes were fabricated by an anodic oxidation process at different preparing conditions. The morphology and structure of the TNT film electrodes were examined by scanning electron microscopy (SEM) and X-ray diffraction (XRD). Photocatalytic activity of the TNT film electeodes was evaluated by the degradation of alachlor in aqueous solution under visible light irradiation. Results indicated TNT film electrode anodized at 20V had well-aligned and highly ordered nanotube arrays and possessed relatively higher photocatalytic activity. In addition, the TNT film electrodes calcined at 500°C for 2 h with the higher degree of crystallinity exhibited the higher photocatalytic activity than other samples calcined at 300°C and 800°C.

Abstract: Using collagen as the raw material, methyl acrylate and vinyl acetate as the soft and hard monomers, ammonium persulfate as the initiator, a surface sizing agent was prepared by the emulsion polymerization method to modified the collagen. The optimum prepared conditions were got by the single factor experiment, follow as m(soft monomer)/m(hard monomer) for 1:2 or 1:1, m(collagen)/m(monomer) for 1:2, the dosage of initiator for 0.8% of monomers amount, the reaction time for 2h. The FT-IR showed that the grafting reaction between vinyl monomers and collagen happened and the vinyl monomers reacted completely. The particle size distribution of the emulsion indicated that its size distribution was uniform and the average size was 0.117μm. The results of application experiments showed that the tensile strength and tearing strength of paper were stronger than that of base paper for 3 times and 1.9 times, after sizing by using the emulsion. The water-resistance of paper was also improved.

Abstract: Bonding strength of the interface of film-substratum is an important factor and key problem that influence the reliability and usage of film-substratum system. The new technology of pulsed-laser shock detection method which analyzes the mechanism and mathematical model of film separation under the action of pulsed-laser shock,. With the example of measuring the adhesion strength of TiN/SKD11 film system, the surface was respectively impacted with pulsed-laser at the range of 650~1000mJ. To observe the surface topography of Impact points by scanning electron microscope, and to identify TiN film failure threshold by the reflected signal detection. By analyzing the experimental result, it was suggested that film/substrate interfacial adhesion strength was 4.954GW/cm2.

Abstract: ^{Superscript text}Thermopile-type Infrared detector is more and more popular in many fields, including infrared spectroscopy, radiometry, security systems and many consumer products. This paper reports a novel n-poly/p-poly thermopile suspension structure with four pairs of thermopiles that compatible with Complementary Metal-Oxide Semiconductor (CMOS) technology and its fill factor is larger than 90%. No additional material is needed to enhance infrared absorption since the passivation layer provided by the CMOS process is sufficient for certain infrared spectral bands. With the selected material parameters the optimal structure parameters are obtained after simulation. Through the theoretic calculation, this novel IR detector has good properties of high responsivity (larger than 1000V/W) and detectivity (larger than 1×108cm Hz1/2W-1) and low response time (shorter than 30ms).