Advanced Materials Research Vols. 295-297

Abstract: Plasma clad Fe-based Al₂O₃ coating was fabricated by the way of delivering powder simultaneously, using high-energy plasma beam as a heating source, while the metallurgy combination of the coating to substrate was formed. The organization and performances of clad coating were analyzed by X-ray diffraction (XRD), metallographic microscope, scanning electron microscope (SEM) and micro-hardness instrument. The results indicate that γ-Al₂O₃ can be obtained by the technology of plasma clad and the good metallurgical bonding of coating to substrate was formed.

Abstract: Multiple types of analysis and examinations are applied to analyze the causes of rupture for a sucker rod made of 20CrMo alloy. Based on the results from macro- and micro-fracture analysis, chemical composition analysis, mechanics test and metallographic examination, the generation of cracks can be attributed to the irregularity and impurity in the coating of sucker rod; the stress fatigue from pulling and pressing and the stress corrosion. There is severe banded segregation, non-metal impurity and un-dissolved ferrite in the interior of the rod, meanwhile the poor heat treatment causes the property differences between the surface and core structures of the rod, thus reduces the overall properties of fatigue- and corrosion-resistance. Stress corrosion makes pits from cracks; the expansion of such corrosion pits reduces the size of effective loading area; and the failure to endure service load due to the reduction of loading area finally causes sudden rupture of the rod.

Abstract: Based on the main problems of tunneling technology and equipment configuration in the south side main entry of Zhangcun colliery, the mechanized line, support way and cement injection technique were investigated and reformed to solve the problems, then a new tunneling technology in south side main entry was proposed. The practical application result show that using different forms of mechanized tunneling lines can improve the loading and transportation efficiency of rock drift tunneling, correspondingly, improve tunneling speed of rock roadway; the support way and cement injection technique in new technology has a positive effect, create a condition for shortening the time of supporting on working face and cement injection and improve the tunneling speed greatly; with the new technology, the work efficiency improved from 0.88m/worker to 0.2m/worker, and increased by 227%.The project of two main entry driving will be completed in a year, and the ventilation system will be formed a year and a half in advance. According to the annual per capita salary sixty thousand Yuan, it can save labor costs 6.12 million Yuan. The good technology and economic effectiveness will be obtained.

Abstract: There were serious transverse corner cracks on continuous casting slab of automobile frame steel plate in Panzhihua Steel before, and study on the control of transverse corner cracks had been carried out. Some effective countermeasures are put forward, such as the optimization of ratio of heat flux density on narrow side and broad side of casting slab (RHFD) and mold powder, as well as the stabilization of casting speed and working condition of caster. Industrial test shows that the transverse corner cracks on continuous casting slab have been significantly reduced, and the lines and peeling defects on hot rolled sheet have been eliminated due to the transverse corner cracks.

Abstract: In this study acrylonitrile-butadiene-styrene (ABS) terpolymer was reinforced with glass fiber. The effects of glass content on the tensile properties of the composites were examined. Increasing the glass content in the ABS matrix from 10 wt% to 30 wt% resulted in improved tensile strength and tensile modulus. To obtain a strong interaction at the interface, SiO₂ at varying concentrations was introduced into the GF composite. The incorporation and increasing amount of SiO₂ in the composites increased tensile properties of the ABS/ SiO₂/GF systems due to the improved adhesion at the interface,. These results were also supported by scanning electron micrographs of the ABS/ SiO₂/GF composites, which exhibited an improved adhesion between the GFs and the ABS matrix.

Abstract: Effect of carbon nanotube(CNT) on structure, strength and tribological behavior of CNT/PU composites is studied in the filler range of 5 vol%. It is found that differences in filler content used to determine the type of structure evolved and patterns of variation of mechanical properties, friction and wear in response to increasing filler content. It is found that wear of low-filled CNT/PU composites is dominated by delamination mechanism and wear resistance changes correlate with structural transformations of the composites. The maximum increase in wear resistance of the PU composites is reached at 2 vol% filling.

Abstract: The several-phased construction of highways and asphalt pavements should be carried out in the following situations：the foundations are made of soft soil or low-quality soil, the filling and digging of the foundations are replaced frequently, the traffic calculations are not accurate, and the fund of the initial phase is insufficient. The design of several-phased constructions can be the basis of remainder life concept according the regulations drew up by America Asphalt Association and combined the regular computing process in our country.

Abstract: The hydrolysis trials of produce microcrystalline cellulose from cotton linter ethnaol pulp by hydrochloric were investigated. Based on 2³ factorial design, fifteen operations were performed by varying S/L, T and t (S/L: solid to liquor ratio, T: hydrolysis temperature, t: hydrolysis time). The charecteristic of product was analyzed by X-RD, SEM and laser granularity distributing apparatus, and compared with commercial MCC. The experimental results indicated that MCC yield and particle size were influenced significantly by those factors. The optimal hydrolysis conditions was S/L=1:7, T=60°C and t=40min, which can resulted MCC yield of 75.3% and size of 21.21µm. Crystallinity of MCC is 63.96% and displayed as rod-shape.

Abstract: This paper evaluates comprehensively the rutting resistance of polyacrylonitrile fiber asphalt mixture by TRLL, AAPA, CPN wheel rutting test and triaxial shear test. The result shows that polyacrylonitrile fiber asphalt mixture is better than cellulose fiber and normal asphalt mixture in improving rutting resistance with any above method. And these methods have relevance in increasing rutting resistance.

Abstract: In order to judge whether the launching site can bear the corresponding pressure and avoid yielding destabilizing destruction during the erection and launching process, the support load of missile erection mechanism in erecting and launching process are analyzed based on the hypothesis that the launching vehicle is bilateral symmetry object. In this paper, analytic method is used to calculate the load to launching site of the wheel davits and launch canister hydraulic legs in the whole launching route, and the place where the biggest load to launching site may appear is also ensured through the calculate procedure and result. Through analysis processing the calculation results, the decision for selecting launching position reasonably, and ensure launching missile safely and reliably are provided. The research conclusions can offer references for selecting and judging intensity of missile launching site when unsupported random launching way is applied.