Advanced Materials Research Vol. 1081

Abstract: The fatigue crack propagation behavior of the prior corrosion 2A12 aluminum alloy fastener involving a central hole was investigated. The virtual crack closure technique (VCCT), is straightforward and not sensitive to the FEA mesh size, was carried out to calculate strain energy release rate and SIFs of AA 2A12 under different stress levels and corrosion years. Based on the VCCT, the simulation carried out to analyze the corrosion fatigue crack growth behavior. It was proved to be convenient to simulate the crack propagation life and the predicted crack growth curve was in good agreement with the experimental results.

Abstract: 5052 aluminum alloy modified with Cu was prepared, and the microstructure of the alloy was investigated throughly. The results show that, the constituents are identified as α (Al), θ-Al2Cu, S-Al2CuMg, Al6(Fe,Cu), Al7Cu2Fe and Si-rich phases. After homogenization at 460°C for 24 hours, the ternary eutectic phases (α-Al + Al2Cu + Al2CuMg) are almost completely dissolved, and there can be observed more binary eutectic phases (α-Al + Si). In addition, the transformation from Al6(Fe,Cu) to Al7Cu2Fe phase occurs during the homogenization. With the increasing of the homogenization temperature, more Al7Cu2Fe phase forms, while the amount of Al6(Fe,Cu) phase gradually declines.

Abstract: Brine corrosion can remain a large obstacle to the rehabilitation project of Missan Oilfields in Iraq. To minimizecorrosion risks, the 13-3/8′′ casing steel, N80,has been employed to examine corrosion behaviors in simulated formation water (i.e., brine). The impact factors of corrosion such as temperature, ion contents, exposure time, and pH have been studied. Also, corrosion inhibitors available in brine have been screened by a static weight loss method. The results showed that effects of environmental and operational variables on N80 corrosion are fairly complicated; the corrosion inhibitor, HN-amph, exhibits excellent corrosion inhibition in brine. This work will provide important information for on-site application.

Abstract: Wire+arc additive manufacture (WAAM) is a high build rate process for production of near-net shape components layer by layer. The performance and quality of the deposited metal are heavily affected by the properties of wires, which are the raw materials for WAAM. Therefore there may be higher requirements for the qualities and properties of wires for WAAM than for welding. External surface qualities, micro hardness, composition and microstructures of five ER4043 aluminium wires were investigated in the present research. The results indicate that the internal and external properties of the wires exert great influence on the performance of the WAAM parts.

Abstract: In this study, wear behaviour of AZ31 magnesium alloy shocked by Hopkinson pressure bar was measured, the microstructure morphology was observed and the effect of high strain rate impact on wear resistance and wear mechanism of the alloy were analysed. The results show that: the wear property of AZ31 is improved by the impacted in a reasonable strain rate, but when the strain rate is high enough, it will cause the alloy inactivation. The wear mechanism of the alloy is main grain-abrasion wear, accompanied with the other form of wear, and there will be adhesive wear with the increase of the strain rate.

Abstract: Microstructures of 9Ni steel quenched at different temperatures were obtained, and a simulated tempering at different temperature was implemented with the DIL850A dilatometer, then the effect of initial microstructure before tempering on the formation of reversed austenite was studied. Results show that the formation of reversed austenite during tempering becomes easier with the decrease of quenching temperature and the increasing of tempering temperature, but the stability may deteriorates with the rapid increasing of reversed austenite in content. Overall, the amount of reversed austenite mainly depends on the tempering temperature, and its formation rate is affected by the quenching temperature because refined quenching microstructure can promote the formation of reversed austenite observably.

Abstract: A novel method called hot-pressing method of preparing porous membrane was firstly reported in this paper. Compared with other method such as none-solvent induced phase separation method, melt-spinning and cold-stretching method, the hot-pressing method was simple, easy to operate, environment-friendly. First, a silica needle arrays (SNA) template with a hexagonal close-packed structure was prepared by TAFE method. Then the SNA template was used to press into the plastic wrap in order to form the uniform pores. After that, a uniform porous membrane was prepared. The diameter of the porous membrane was affected by the pressure of hot-pressing as well as the hot-pressing temperature.

Abstract: Interfacial potential of Fe [110]/TMC[001] (TM=V, Nb and Ta) are obtained with adhesive energy and the inversion method. The interfacial stability and tensile fracture properties of the semi-coherent interfaces of the Fe [110]/TMC[001] (TM=V, Nb and Ta) are studied based on the interfacial potentials. Results indicated that Fe/VC interface is more stable than the Fe/TMC (TM=Nb and Ta) interfaces.

Abstract: Based on the research of experiment content and connecting with the current of Daqing oil field polymer injection condition [1]. We make the following experiment scheme design that focus on the study of polymer injection time. We analyzes the change of the ultimate recovery trend and combines with the change of moisture content and injection pressure indicators. We summarize the change of the polymer injection time under the condition of indoor physical simulation experiment on the influence of ultimate recovery to guide the late oil field polymer injection development plan design [2].

Abstract: As a common kind of surface defects on multi-crystalline silicon solar cells (about 65% of total defects). Based on HALCON image processing library, an automatic silicon wafer surface spot defects detection and classification system has been developed: captured color images via CCD image sensor, located wafers and spots, extracted the spot features, computed and separated the qualified regions from the unqualified ones by SVM classifier. The experimental result showed a high accuracy of 95.7% and fast image analyzing and classifying process (less than 600ms).