Applied Mechanics and Materials Vols. 599-601

Abstract: In the present study, the texture of friction-stir-weled 5A30 aluminum alloy was investigated by EBSD technology. Cubic texture {100}<100> is obtained in the shoulder-affected region of NZ due to the complete recrystallization. The dominate texture in the pin-affected region of NZ is the {112}<110> B/ simple shear texture induced by the rotation pin.

Abstract: In this paper, the bamboo-poplar composite oriented strand board (OSB) with different hybrid ratios were aged under the standard of ASTM D1037 to evaluate its weathering performances. The thickness swelling (TS), water absorption, modulus of rapture in perpendicular direction (MOR_⊥), modulus of elasticity in perpendicular direction (MOE_⊥) and internal bonding (IB) of specimens were tested. The results showed that the reduction rate of TS ranged from 21% to 69%, which increased with the poplar ratio increasing; the growth multiple of 24h water absorption of bamboo-poplar composite OSB were at the similar level, the values of which were much smaller than that of the pure bamboo or poplar OSB; the maximum and minimum retention rate of MOR_⊥ and MOE_⊥ belonged to pure bamboo and poplar OSB respectively, retention rate of MOR_⊥ of the bamboo-poplar composite OSB rose with the increment of poplar ratio, while retention rate of MOE_⊥ and IB of bamboo-poplar composite OSB were similar and the hybrid ratio 2.5:7.5(bamboo: poplar) obtained the maximum IB retention rate of 16%. Through detailed comparison, the bamboo-poplar composite OSB with the hybrid ratio 2.5:7.5 performed the best after aging.

Abstract: Double composite flexible absorbing fabrics were fabricated according to the resistance matching principle and electromagnetic spreading regulation. The surface layer, composed of stainless steel core-spun yarn, easily realized matching to the free space. The under layer made up of iron fiber which had significant microwave absorbing effects. The reflectivity of fabrics were measured by the means of "arch testing method" in the range from 2~18 GHz with the change of fabric specifications. The results showed that the reflectivities of 12 groups can below-15 dB in the 20 groups testing and the second group which below-20dB was thin and only 440g/m² with the optimized fabric specifications.

Abstract: Through the corrosion test method of different active mineral admixture concrete under bending loads,we studied the C50 concrete specimen under bending loads on corrosion resistance and with the relation to corrosion time about the condition of specimen in saline soil. The results showed that the maximum corrosion effect on concrete with the saline soil in the short-term (1 year) appeared from the sixth to the ninth month (under maximum corrosion loss coefficient), but in other time is smaller. Concrete with gas forming admixture exhibit best corrosion resistance, fly ash concrete come second and normal concrete show worst performance in corrosion resistance, we propose corrosion prevention measures for concrete structures under loads in saline soil region to improve the durability of concrete structures according to the result.

Abstract: The friction and wear properties of Cu-Te-Li alloys under dry sliding condition were studied by M-200 wear testing machine. The morphology and chemical composition of worn surfaces were analyzed by SEM and EDS, thus the effect of aging treatment on friction coefficient, wear rate and wear mechanism was discussed. The results showed that Te element could improve the wear resistance of copper alloys. With Te content increasing, the friction coefficient of Cu-Te-Li alloys declined slightly and tended to be stable as a whole, while the wear rate decreased obviously. During the process of dry sliding friction, adhesive wear was the dominant mechanism, with oxidative wear coexisting. But for the Cu-Te-Li alloys after aging treatment, abrasive wear appeared and adhesive wear was intensified, especially at higher friction velocity.

Abstract: The mean projected ranges and range straggling for energetic 200 – 500 keV Yb ions implanted in 6H-SiC were measured by means of Rutherford backscattering followed by spectrum analysis. The measured values are compared with Monte Carlo code (SRIM2012) calculations. It has been found that the measured values of the mean projected range are good agreement with the SRIM calculated values; for the range straggling , the difference between the experiment data and the calculated results is much higher than that of .

Abstract: Attenuation coefficient is frequently-used for ultrasonic creep inspection in metals. However, in practical inspecting, e.g. thick wall weldment in high temperature pipings, it is usually difficult to measure the accurate propagating distance of ultrasound, which results in an inaccuracy of attenuation coefficient calculation. Therefore, a modified method for attenuation coefficient calculating was proposed here, in which the flight-time of ultrasound was substituted for propagating distance. The new calculated attenuation coefficient was named as flight-time-attenuation parameter, and had a unit as dB/us. A uniaxial tension creep experiment with pure lead was conducted to verify the detecting ability of this new parameter. Two piezoelectric wafers were pasted on the pure lead specimen, and ultrasonic testing was carried out simultaneously without interrupting the tension procedure. Attenuation coefficient and flight-time-attenuation parameter were calculated with inspecting signal acquired from creep specimen, and compared with each other. The results showed that two ultrasonic parameters had the same variation tendency along with creep procedure, and flight-time-attenuation parameter had a better sensitivity. Accordingly, the flight-time-attenuation parameter could be used for ultrasonic creep inspection in metals, and worked as a replacement of attenuation coefficient calculated with propagating distance. Another creep inspecting experiment with P91 steel weldments was conducted to verify the practicability of the new parameter, in which the new flight-time-attenuation parameter showed a good distinguishing ability for different creep status.

Abstract: Anti-corrosion performance of titanium alloy/pure titanium was studied from the aspect of electrochemistry. Anode polarization test and electrochemistry impedance spectroscopy were applied to investigate the influence of different ionic solution on corrosion behaviors of titanium alloy and pure titanium. From the X-ray diffraction (XRD) and scanning electron microscopy (SEM) analysis on the titanium samples after surface corrosion or not, we found that the corrosion performance of pure titanium was more sensitive to ionic solution than that of titanium alloy, and oxidant ions played a determine role in the corrosion process of pure titanium.

Abstract: This paper attempts to use the I-deas software to analysis the reinforced concrete box girder temperature field in early stage, focusing on the analysises under the action process of water thermal and reinforced concrete box girder variation law of temperature field under time histories.

Abstract: For achieving sufficient flame retardancy, high magnesim hydroxide (MH) content is needed in MH flame retardant Acrylonitrile-butadiene-styrene copolymer (ABS) composites (ABS/MH), which will cause a great decrease in mechanical property and difficulty in preparing samples for measurement. We prepared ABS/MH filled high 60.0% flame retardant by compounding ABS and modified flame retardant MH, fumed silica (SiO₂) and zinc borate (ZB) via TX-10 phosphate/polyacrylate latex and studied the effect of a small amount of SiO₂ and ZB with MH in ABS for improving the thermal decomposition of ABS/MH. The thermal stability of the modified flame retardant could meet the processing temperature of ABS. The incorporation of ZB, SiO₂ or SiO₂/ZB could improve the thermal stability of ABS/MH.