Advanced Materials Research Vols. 415-417

Abstract: In this paper, the traditional steel engine hood is analyzed using finite element method firstly, and then the basic performance requirements of the hood is obtained. Based on the principle of equal stiffness, the design process is executed on carbon fiber composite hood. Afterwards according to the property of this composite, the whole optimization process of composite hood from conceptual design to detailed design is accomplished by ways of free size optimization, parameters optimization and stacking sequence optimization. The optimal structure of carbon fiber composite engine hood can be obtained by comparing the results of optimization design. Carbon fiber can put lightweight into practice , and the developing time of composite hood can be sharply reduced .

Abstract: The NiCrAlY coatings were deposited on 38CrMoAl substrate by a laser hybrid plasma spraying (LHPS) technology in this study. The coatings’ microstructures and anti-corrosion performances with different laser power were characterized using an optical microscope, a scanning electron microscope, and the Neutral Salt Spray(NSS) test. The test results indicate that the laser power has great effect on the microstructure and performances of the LHPS coatings. And when the laser power is appropriate, it can make the coating has more compact and homogeneous microstructure, exhibit less porosities or micro-cracks, higher bonding strength and more excellent anti-corrosion performance.

Abstract: Alumina-Tungsten Carbide (Al₂O₃-WC) composites were synthesized by self-propagating high temperature synthesis (SHS) from a powder mixture of WO₃-C-Al. The reaction was carried out in a SHS reactor under static argon gas at a pressure of 0.5 MPa. The standard Gibbs energy minimization method was used to calculate the equilibrium composition of the reacting species. The effects of carbon mole ratio in precursor mixture and diluents of NaCl and Al₂O₃ on the Al₂O₃-WC conversion were investigated using X-ray diffraction and scanning electron microscope technique. The as-synthesized products of Al₂O₃-WC₂-WC powders were concurrently formed and the reduction of W₂C phase was found when added diluents in precursors.

Abstract: The key to analyze the dynamic characteristics of rubber products in frequency domain is to obtain the frequency correlation viscoelastic models of rubber. Firstly, an improved anti-optimization method using the parallel computing module of ISIGHT integrated ANSYS and MATLAB was proposed to identify the parameters of frequency correlation viscoelastic model for rubber. Secondly, the method is applied to obtain the viscoelastic model of a rubber metal ring, of which the frequency range is from 2Hz to 10Hz, and comparison between the results and the experimental results shows that the proposed method is effective.

Abstract: Calcium carbonate nanoparticles (nano-CaCO₃) filled powdered styrene-butadiene rubber (P(SBR/CaCO₃) was prepared by adding nano-CaCO₃ particles, encapsulant and coagulant to styrene-butadiene rubber (SBR) latex by coacervation, and the particle size distribution, structure were studied. Scanning electron microscopy (SEM) was used to investigate the (P(SBR/CaCO₃) particle structure, and a powdering model was proposed to describe the powdering process. The process includes: (i) the latex particles associated with the dispersed nano-CaCO₃ particles (adsorption process) to form “new particles” and (ii) the formation of P(SBR/CaCO₃) by coagulating “new particles”. The SEM results also shown that the nano-CaCO₃ and rubber matrix have formed a macroscopic homogenization in the (P(SBR/CaCO₃) particles and nano-CaCO₃ dispersed uniformly in the rubber matrix with an average diameter of approximately 50 nm.

Abstract: For getting better properties and simplifying processes, the in-situ synthesized Al₃Ti/Mg composites were prepared by vacuum hot-pressing. Phase composites and microstructures of composites were researched by methods such as XRD and SEM. The result indicated that fine Al₃Ti particulates with size of 0.5~2.0 μm were distributed uniformly in Magnesium matrix and combined closely with the matrix. The mechanism of in-situ synthesized Al₃Ti in Magnesium matrix was discussed and a model of micro structural reaction between Ti and Al was brought forward.

Abstract: Materials Science typically engages research expertise from fields such as engineering, chemistry and physics. This paper will examine how industrial design successfully contributed to timber materials science in the initial phases of basic research. Research from two PhD studies, completed in conjunction with the Australian Cooperative Research Centre (CRC) for Wood Innovations, will be used as case studies. These case studies discuss examples from research projects investigating new Microwave Modified Timber (MMT) materials development along with surface modified timber. Findings concur that industrial design research was beneficial to early scientific experiments.

Abstract: The early disease of semi-rigid asphalt pavement disease will seriously affect the quality and durability of road usage and the life of the road. Water into the pavement layer cause water content increases and the strength greatly reduced in primary or sub-base material which contends more soil and greater soil plasticity index. Resulting in premature failure of asphalt pavement, and the road surface rutting greater is the insufficient primary strength. The use of water overdose primary stability can fully play its high strength and low cost advantages, but also has a low shrinkage, minimize shrinkage cracks.

Abstract: A siloxane-containing dianhydride, succinic anhydride terminated polydimethylsiloxane (DMS-Z21) was selected to cure diglycidyl ether of bisphenol-A based epoxy resin (DGEBA). The cure kinetics and thermal properties were investigated by nonisothermal and isothermal differential scanning calorimetry (DSC) and thermogravimetric analyses (TGA), respectively. The activation energy (E_a) of the curing reaction was obtained based on the methods of Kissinger and isothermal measurements. The results of the thermogravimetric analyses of the DGEBA/DMS-Z21 system showed that the thermal stability of the DGEBA/DMS-Z21 system was slightly higher than the DGEBA/MeTHPA system.

Abstract: Self-compacting concrete-filled steel tube is different from ordinary self-compacting concrete in many aspects. According to the demands of on-site construction conditions and construction technology of continuous pumping lift-up method for the project of Huaxi No.1 steel tube arch bridge, property requirements of self-compacting concrete filled steel tube were proposed in this paper. By using the preparation techniques such as optimization of basic parameters of concrete mix proportion, admixture composition and mineral admixture addition, self-compacting concrete filled steel tube was prepared with the properties such as initial slump more than 24cm, initial slump flow above 650mm, T₅₀ between 5s and 15s, no slump loss for 4h, no bleeding, strength grade above C60 and shrinkage-compensation etc. It was applied in the steel tube arch bridge project successfully using the construction technology of pumping lift-up method.