Applied Mechanics and Materials Vol. 312

Abstract: Although the research on the safety of the nanomaterials has made some progress, there are still some problems, such as: lacking the knowledge of the entire life cycle of nanomaterials----the production, the application and the transformation; more research on the safety of the nanomaterials which enter the body through inhalation, but less on other approaches; the lack of ideal reference materials; a shortage of appropriate toxicological endpoints in vitro experiments and standards to determine the dose. This paper mainly analyzes the security and evaluation of nanomaterials.

Abstract: This paper was reported a method of making intumescent flame retardant from pentaerythritol, Phosphorus oxychloride and melamine, The effects of molar ratio, reaction temperature and time on the reaction were obtained ,and the best reaction condition was established : the molar of PDD and melamine is 1:2.5, reaction temperature60°C, reaction time about 10h, the yield was 82%.

Abstract: A building in the long-term use process, with the effect of internal or external, artificial or natural factors, with the time went by, these will occur material aging and structural damage, this is an irreversible process, this kind of damage accumulation will lead to structural performance degradation, bearing capacity decline, durability reduce. For new buildings, if do the structure performance degradation research in the beginning of completion, it can not only master its structure member performance degradation, reveal the potential dangers, and at the same time can also according to the results of the study formulating the reasonable use and maintenance program, improve the safety performance of the building and prolong the use fixed number of year.

Abstract: With orthogonal tests the effects of grain refiners and modifiers, Al-10Sr, rare earth (RE) and Al-Ti-5B, on the mechanical properties of Al-Si alloy for automobile cylinder blocks were studied. The best result occurred when the proportion of refiners and modifiers was Al-10Sr = 0.1wt%, RE = 0.3wt%, Al-5Ti-B = 0.8wt%. With SEM and EDS the as-cast microstructures of materials after grain refining and modification were observed and analyzed. Tiny branch-shaped AlSi phase, thin-striped AlCu phase, new small bone-shaped AlSiMn phase, new leaf-shaped or feathered B(AlCuCe) phase as well as the phases of other metal compounds made the as-cast microstructures more complicated and more compact after grain refining and modification. Some brittle phases reduced in size obviously and distributed in the grain boundaries of plastic α-phase in network, which acted as intercrystalline strengthening to certain degree. During the tensile deformation these brittle phases could reduce the stress concentration, impeded dislocation movement, and then strengthened the alloy matrix. In addition after grain refining and modification the porosity was significantly reduced.

Abstract: The fatigue tests on 15CrMo steel specimen were carried out and the metal magnetic memory (MMM) signals were detected. The experiment shows that the magnetic signals of specimen contain the information of stress distribution in the material inside. Furthermore, the experimental results show that the magnetic signals increase initial while then decrease slightly with the stress increase from 0kN to 200kN. Though analysis the MMM signals induced by different tensile stress within the plastic region of the specimen, a simple model was derived. The experimental results are consistent with the calculated results based on the Jiles-Atherton model.

Abstract: PET is a ubiquitous material in modern life which is used in diverse applications from drink bottles and film to shirts and fabrics. A brief introduction of PET is given in this report, concentrating on the following aspects: the preparation process, the properties and the application of this product. Market perspectives and some recommendations of PET industry are also discussed in this report based on the current market analysis.

Abstract: The effect of Gd addition on the microstructures and mechanical properties of Mg-5Sn-Zn-Al alloy was investigated with variations of Gd contents. These results show that adding Gd can effectively refine the grain size and growth. In addition, the solubility of Gd increases the lattice constants of α-Mg phase. Accordingly, the tensile properties of the as-cast Mg-5Sn-Zn-Al alloy are improved by the addition of Gd. The Mg-5Sn-Zn-Al-0.4Gd exhibits the highest tensile properties, and the values of the yield and ultimate tensile strength and elongation are 111 MPa, 188 MPa and 18.0%, respectively.

Abstract: Paper transferring gripper is a key part of printer. In this work, plasma spray technology was adopted for the coating of 5 different metal oxide ceramic layers on metallic substrate. The friction and wear performance of different plasma-sprayed metal oxide ceramic coating on the gripper surface were comparatively studied by friction and wear test. Results suggested that compared to 100% Al2O3 and 100% Cr2O3 ceramic coatings, Al2O3/Cr2O3 composite coatings had a higher friction coefficient and wear amount. Abrasive wear was the dominant wear mechanism for Al2O3/Cr2O3 composite coatings, while fatigue wear was dominant for 100% Al2O3 and 100%Cr2O3 ceramic coatings.

Abstract: In order to improve the radial strength of energy storage flywheel, this paper design and analyses the multi-ring flywheel rotor in different conditions by finite element method. From the results, we can confirm that interference condition is critical influence on the stress gradient of the rim. The results can provide a guide for high energy density multi-ring composite flywheel rotor design.

Abstract: Iinteractions of copper and wood components in the ACQ-D treated Chinese fir (Cunninghamia lanceolata Hook.) after hot water and hot air post-treatments were studied by using Fourier transform infrared spectroscopy (FTIR). Compared to Chinese fir (Cunninghamia lanceolata Hook.) without any treatments, significant reduction was noted at 1735±5 cm-1 assigned to carboxylic groups in the hemicellulose in all the samples with different post-treatments. The intensity of bands at 1655±5cm-1, 1510±5 cm-1 and 1265±5cm-1 are assigned to ketone carbonyl stretching groups, aromatic skeletal vibration and acetyl ether linkage in lignin were also decreased after different post-treatments compared to untreated Chinese fir. These results imply the fixation reactions of copper in the treated wood have been promoted by the post-treatment conditions, and the major bonding sites of copper in the treated wood are located in the wood lignin and hemicellulose.