Advanced Materials Research Vols. 228-229

Abstract: A novel suspended ceramic hot-plate and wire-free bonding interconnection was investigated. The device was made on the popular alumina ceramic flakes with a platinum heater prepared by lift-off process. The structure of suspended beam was machined by laser micromachining technique. This contribution presents first results for single-layer’s ceramic hot-plates that include design, manufacturing and tests of such devices. The results show that the ceramic hot-plate has lower power consumption (280 mW at 400 °C) than classical ceramic gas sensors. Moreover, it has less expensive manufacturing and bonding process than Si manufacturing technology. Low power consumption and good performance at high working temperature (600 °C or more) makes it possibly to be used in some specific applications for gas sensors.

Abstract: In most superplastic forming process, one or more sheets of superplastic grade materials are heated and forced onto or into single surface tools by gas pressure. Since the assembly includes only clamping dies, temperature chamber and regulated gas pressure to provide forming force, the assembly is easy to use for aircraft components. However, it is not easy to control process variables at high temperature. This paper presents an economic machinery method to develop hot press machine for manufacturing complex contoured components using superplastic forming and diffusion bonding technology.

Abstract: A new-type of dredging equipment for the coal bunker is designed to solve the clogging problem, which avoids the disadvantages of the existing dredging technology used in the collieries. The new dredging method borrows ideas from air cannon dredging technology, and applies dynamic high pressure generation principle. In the process of dredging, the rubber bullet in the launch canister is accelerated by the controlled high pressure air, and impacts the coal in the arch with high speed so as to recover the coal bunker. The dredging mechanism and process are expatiated and the main structures of the dredging equipment are introduced. The structure of the new type dredging equipment for the coal bunker is simple and the equipment is of high adaptability and safety.

Abstract: Lateral vibration equations of fluid-conveying pipes system are high order partial differential equations, and the analytic solution is difficult to obtain, so in this paper the numerical solution is obtained by the finite element method. Firstly, the finite element equations of lateral vibration of fluid-conveying pipes were set up, and four kinds of boundary constraints were proposed. The modal analysis of vibration system was carried out by using mode decomposition method, and the system responses were solved by using Newmark method. The impact of pipe span, flow rate, fluid pressure, flow rate disturbance and fluid pressure disturbance on the modes and responses of vibration system were studied. The research results provided theoretical support for the vibration reduction research of fluid-conveying pipes.

Abstract: CdO nanoparticles with different sizes were synthesized by a simple thermal decomposition reaction of precursor obtained by room-temperature solid-state grinding reaction between Cd(CH3COO)22H2O and NaOH in the presence of PEG400. Composition, structure and morphology of the products were analyzed and characterized by X-ray diffraction technology, Transmission electron microscopy and Fourier infrared spectra. The formation of CdO nanoparticles is thought that the nucleation rate of the reactive system is far excess the growth rate of particle. Optical properties of the products were recorded, and the results show that Ultraviolet-visible (UV-vis) spectra exhibit distinct blue shift in comparison with them of the bulk CdO, which is because that the quantum confinement effect of the products is larger than the Coulomb effect. Photoluminescence (PL) spectra exhibit green and red emission bands around 520 and 720 nm respectively.

Abstract: Micro-extrusion of a Zr-based bulk metallic glass in its super-cooled liquid state is explored as a method to create objects of cup-shaped micro-parts. The effects of overall dimensions of the samples and the ratio of inner diameter to out diameter (i) on the forming are determined. The results reveal that the apparent viscosity of the forming liquid increases along with the rises of i or with the decrease of the overall dimensions, and the increasing speed is more quickly while i is greater than 0.833, which suggest that there exists significant size effect. More generally, the results suggest that large i, and a low overall dimensions are attributes indicating difficulty for forming.

Abstract: CFRP is a new kind of building materials popularly used in structure strengthening. When CFRP is used to strengthen the masonry structures built by the traditional building materials-bricks and mortar, good reinforcing effect will be achieved. But there are still a lot of theoretical difficulties in CFRP’s application in structure strengthening. The paper studied the mechanical performance of CFRP strengthening the masonry structures by finite element analysis. Ansys is used in the paper to establish discrete models of brick walls strengthened by CFRP. In the models, mortar and blocks are given different material properties and simulated by contact elements and plane elements respectively. Through the comparison of the results of finite element calculation and experimental study, the mechanical performance of the walls is studied. The study shows that contact elements can simulate the mortar very well and the mechanical performance of the discrete models presented in the paper meets the actual masonry structure well too; in addition, the strengthening material-CFRP can improve the mechanical performance of the walls effectively.

Abstract: According to China Association of Automobile Manufactures statistics, China’s automobile production and sales ranked first in the world in 2009. Although China has become a big country of automobile manufacture, the research and design capabilities of automobile is still weak, especially in styling design. How to use computer aided technology to promote the development of car styling design is the aim of this article. CAS (computer aided styling) may be is a good choice. First, comparing the different among traditional styling design process, CAD design process and CAS design process, this article points out the benefits brought by CAS; Second, this article explain the details of CAS design in car styling design; Finally, this article analysis the character of CAS which is important to apply CAS correctly. If Chinese auto companies could apply CAS well in car styling design, the industry of China automobile will enter a new phase.

Abstract: B4C ceramic nozzle was produced by hot pressing, and wear behavior of the nozzle by SiC, white emery and umber emery abrasives were investigated, erosion wear mechanisms based on stress states analyzing with finite element method were studied. Results showed that the greater the hardness and grit size of abrasives, the more mess loss of the nozzle, the maximum stress appeared in entrance area of the nozzle and minimum stress in middle area, while the stress of exit area was lower than entrance area and higher than middle area. The nozzle exhibited a brittle fracture induced removal process in the entrance of the nozzle and a stress fatigue induced removal process in the middle of the nozzle under the condition of SiC abrasives impacting, and a stress fatigue induced removal process under white and umber emery abrasives impacting.

Abstract: In order to improve the performance of forest fire protection equipment, this paper proposes a new design concept of modern forest fire helmet. The scheme combines the functions of infrared thermal imaging, wireless communication and emergency oxygen making, which not only meets the security requirements in firemen’s present working, but also accords with the development of fire helmets at home and abroad. This helmet adopts the design conception of integration structurally, its weight and operation difficulty are both reduced, at the same time, accords with the Man-Machine Engineering. Moreover, using the three-dimensional processing software, this study realizes a simulation model of the designed forest fire helmet.