Advanced Materials Research Vols. 335-336

Abstract: The moisture absorption characteristic of the humidity-controlled materials at different relative humidity was studied by experiment and the moisture equilibrium content under different humidity condition was obtained. At the same time, the humidity-controlled composite building blocks in greenhouse were successfully developed. The experiment of the humidity-controlled composite building blocks shows that the humidity-controlled composite building blocks can realize the humidity control without the high power consumption, operation inconvenience or polluted the environment etc. compared with the traditional dehumidification method. The humidity-controlled composite building blocks in greenhouse have the very good application prospects.

Abstract: This article is intended to outline a novel concept of interlaminar 3-3 connectivity of fiber-reinforced laminated composites. This microstructure is typically realized by using thorny ZnO whiskers exactly located in the interlayer of glass or carbon fabric for RTM. From the initial testing, the interlaminar shear strength (ILSS) is noted to increase up to 150% while retaining the most other in-plane properties. Mechanistic penetrating and pinning are considered to be the dominant mechanism of interlaminar toughening effect, with the evidence of the broken, fragmented and pull-out whiskers observed in the fracture morphologies.

Abstract: Carbon-encapsulated iron-based alloy nanoparticles with a core-shell structure were prepared by detonation decomposition of nitrate complex explosives containing multi-metallic ions. The size and magnetic properties of the as-prepared composite particles were revealed by X-ray powder diffraction, transmission electron microscopy, energy dispersive X-ray detector and magnetic measurements. Results showed that the different sizes of the ferronickel and ferrocobalt nanocrystal core and the thickness of the carbon shell could be yielded by adjusting the component materials of the explosives. The composite particles had a gamma- or alpha- ferronickel or bcc-ferrocobalt nanocrystal core with a coating of graphitic carbon layers. Magnetic measurements indicated these composite nanoparticles were superparamagnetism at the room temperature, with some variation in the values of saturation magnetization, remanences and coercive forces.

Abstract: The key problem to prepare carbon nanotubes (CNTs) reinforced ceramic matrix composites is how to break up massive agglomerates of CNTs and disperse uniformly CNTs. We obtain the CNTs-Al₂O₃ composite powder by shear treatment on melted CNTs-Al₂O₃-agents mixture. Microstructure observations of CNTs-Al₂O₃ composite powder show that CNTs can be dispersed uniformly by shearing process. The rheological results also affirm the conclusion. According to the rheological theory, we build the ideal dispersion model of CNTs-Al₂O₃ suspension system and discuss the dispersion mechanism.

Abstract: Based on the combinational method of pseudo ternary phase diagram and orthogonal design and taking the study on the imidacloprid microemulsion as example, the method of preparing the pesticide microemulsion was creatively brought forward to remedy the situation of the lack of the research on compounding the microemulsion. The experimental results and the date analysis show that our method is simple and effective, and were expected to provide new ideas and technical methods for the development of pesticide microemulsion.

Abstract: Four Ti(C, N)-based cermets was fabricated from different size of ceramic powder by the conventional powder metallurgy technique. Microstructure, fracture surfaces and crack propagation path of samples were observed by SEM, and mechanical properties such as transverse rupture strength, hardness and fracture toughness were measured. Results show that with the refinement of the raw TiC/TiN powders, the black cores and ceramic grains tend to be finer, the gains with white core-grey rim structure obviously increase, and the microstructure of cermet becomes inhomogeneous. The cermets fabricated from fine powders possess higher porosities. Compared with the cermets made from micron ceramic powders, the cermets fabricated from ceramic powders containing nano powder possess higher transverse rupture strength and lower fracture toughness. When the cermet is fabricated from micron TiC/nano TiN powders, its combination property is the best.

Abstract: In this paper, the microscopic features of damage and texture of a wheel tread in high-speed rail were investigated by EBSD. The microscopic sample was cut from the wheel tread zone of a used high-speed rail wheel. It was found from the microscopic investigation that the density of austenite distribution is increased near the wheel tread, and the damage voids distribute far away from the wheel tread zone. The texture analysis with two magnify zone indicated that there exists large amount of twin-crystal within the ferrite in the dimension of 20 micrometer, and the dimension of austenite and martensite decreases in the edge zone of the wheel tread.

Abstract: According to internal heat and moisture transfer coupling equations for the humidity-controlled composite materials in greenhouse, the analytical solutions are obtained under the steady periodic conditions, then the moisture desorption and adsorption properties of humidity-controlled composite materials in a closed space are investigated. It shows that the air humidity ratio in the closed space changes periodically in consistent with the air temperature. The ratio of the absolute humidity amplitude to the air temperature amplitude is a constant, which can be taken as a criterion to evaluate the humidity control performance of the material. A simple method, the close box and heat impulse method is put forward to measure the constant value. It can directly embody humidity-controlled traits of materials under the condition of periodic heat and moisture.

Abstract: According to the finite element method, this article has established the FML’s finite element model. By comparing to the test data and studying of the tensile behavior of FML, it has verified valid of the model. When the aluminum layer yields under the tensile load, the composite layer has the most tensile load. And the model has been developed to predict the stability influenced by the rib’s height.

Abstract: One kind of bismaleimide resin (BMI) was prepared from Michael addition reaction with modification carbon nanotubes (m-CNTs). CNTs were modified by N-phenyl maleimide (N-PMI) and ethylenediamine. The effect of modification was determined by NMR spectra and Raman Analyser. The cure kinetics, thermal behavior and mechanical property of carbon nanotubes/bismaleimide-o,o-diallyl bisphenol A resin (CNTs/BMI-BA) were studied. It was found that this kind of CNTs can be easily dispersed in high performance resin only with a slight stirring. The curing apparent activation energy (Ea) decreased with the increasing amount of m-CNTs. The maleimide-CNTs could fully express its unique mechanical properties and dramatically increase the reaction activity, the storage modulus, impact strengths and bending stress of the CNTs/BMI-BA composites while the CNTs-COOH reduce the important mechanical properties. These critical enhancements will definitely help to attract more researches in this field.