Advanced Materials Research Vol. 744

Abstract: SCR catalyst is the core of SCR technology. More attention to manganese oxide-based catalysts has been paid due to their excellent catalytic activities in low-temperature selective catalytic reduction of NO_x by NH₃ (NH₃-SCR) in recent years. In this paper, the preparation method of honeycomb cordierite Mn-Ce/TiO₂ catalyst and denitration performance is studied. Different amount of TiO₂, Mn and Ce are supported on the cordierite ceramic and the SCR catalytic tests are conducted. In the tests, the influence of Mn/Ti molar ratio on the denitration performance and the effect of reaction temperature, inlet NO concentration, volumetric space velocity and ammonia nitrogen ratio on the denitration performance are found. The results show: (1) Mn/TiO₂ catalyst has the highest catalytic activity when the Mn/Ti molar ratio is 0.4. (2) The optimum reaction condition of honeycomb cordierite Mn-Ce/TiO₂ catalyst denitration reaction is the inlet NO concentration is 0.075%, volumetric space velocity is 4000 h ¹ and ammonia nitrogen ratio is 1.05.

Abstract: Thermo-electropulsing rolling (TER) process, which combined the electropulsing treatment with the conventional warm rolling process (WR), was applied to manufacture AZ31 magnesium alloy strips in the current study. Influences of TER process and WR process on microstructure and mechanical properties of AZ31 Mg alloy were studied. TER process was found to induce and accelerate the dynamic recrystallization (DRX) behavior of the samples at a relatively low temperature within a short time. Besides, TER process could obtain samples with better mechanical properties than that of WR process.

Abstract: A production process of high tensile strength spring steel is discussed in this paper. Sufficient aluminum was added into ladle during tapping and barium alloy was used in late refining process. It was found that the refining slag with high basicity is strongly deoxidized after refining, with total oxygen content being less than 10×10^-6 in billet. Thus, the oxide inclusions in the steel is finished the transformation during refining and some complex oxide inclusions are remarkably removed at steelmaking temperature. The tensile strength over 2.0GPa and the extension rate up to 10% are obtained for the spring steel after quenching temperature at 900oC and tempering at 410 oC. So, the strength and plasticity of the steel are improved obviously.

Abstract: The composite leaf spring for trailer truck is developed with weight reduction 60% relative to steel spring, which can be benefit to environment protection and energy saving. In this work, the composite leaf spring is designed and analyzed by finite element method. Then the experimental tests are conducted on the composite leaf spring fabricated by the hot molding process. The spring rate and the maximum load capacity are measured, which have a good agreement with the design results.

Abstract: Some unsatisfactory characteristics of Ti2AlNb-based alloys restrict its practical application, such as the insufficient high temperature oxidation, corrosion resistance and poor wear resistance. The double glow plasma surface chromizing can improve their wear resistance, however the hot corrosion properties of surface plasma chromised Ti2AlNb-based alloys were little investigated. The microstructure, composition and surface hot corrosion morphologies of Ti2AlNb-based alloy were analyzed by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The XRD of alloying layer indicated that the Cr-Nb alloy phase was the main composition, including the compact and uniform Cr2Nb phase, which was benefit to improve the hot corrosion properties of alloy.

Abstract: Carbon Capture and Storage (CCS) is one of the global leading methods that could potentially retard the speed of climate change. However, CCS on point sources can only slowdown the rate of increase of atmospheric CO2 concentration. In order to mitigate CO2 released by previous emissions, a more proactive alternative is proposed where CO2 is directly extracted and captured from air Direct Air Capture (DAC). This paper presents a technical overview from our current research of a novel DAC concept which features a phase of axial compression to adapt pre-capture atmospheric air to a level suitable for carbon capture. Also detailed in the paper is the feasibility study addressing several key issues: the energy consumption and overall capturing efficiency of the proposed DAC system.

Abstract: Sol-Gel Coating was used to prepare nanocrystalline titanium oxide film, with which some metal ions were mixed up. In the end, XRD and SEM were used to analyze the composition and the property of the morphology, and then ultraviolet light was used to test the super-hydrophilic property. The results show that the photocatalytic property of the metal ion-doped films is stronger than that of the non-doped TiO₂ films, but weaker than the metal ion-doped SiO₂/TiO₂ films. For the doping 0.05% TiO₂ films, the Ce-doped titanium dioxide on the degradation of methyl orange is the slowest. After calcined at 500°C for 2 hours, rutile and anatase crystals are mixtured; Grain size of the films is in 42.5-85.7 nm.

Abstract: In this paper, low cis-butadiene (LCPB) is used in the process of polymerization of HIPS to study the influence of the polymerization condition on the particle size of rubber and mechanical property. It can be discovered from the study that the particle size was increased from 300nm to 500nm with the decreasing stir. The test of mechanical property shows that with the increase of content of rubber, elongation at break and impact strength on cantilever increase, but stretching strength decreases. On condition of 100 rpm, when the content of rubber increases from 3% to 9%, elongation at break increases from 21.9% to 25.0%, stretching strength decreases from 30.5 MPa to 23.9 MPa, and the cantilever impact strength increases from 5.4KJ/m2 to 9.3KJ/m2. On condition of 200 rpm, when the content of rubber increases from 3% to 9%, elongation at break increases from 21.4% to 29.1%, stretching strength decreases from 28.7 MPa to 20.8 MPa, and the cantilever impact strength increases from 5.2KJ/m2 to 8.1KJ/m2. Keywords: HIPS, mechanical properties, morphologies, T117 initiation

Abstract: Li/graphite fluoride (GF) cells are well known to have high energy density, good reliability, long shelf life, safety and wide operating temperature. However, the low electronic conductivity and discharge potential of Li/GF cells obviously limited its applications. In order to improve the energy performance of Li/GF cells, an efficient method is to increase the transportation ability of Li⁺ in cathode. The decreasing layers of graphite could increase the fluorinated surface between carbon and fluorinating agent, resulting in the emerge of the C-F bands of fluoride. Multi-walled carbon nanotube (MWCNT) can be considered as a curly materials of nature graphite sheets. This barrel structure shows much more C-F bands when they were fluorinated and turned into fluorinated MWCNT. And these emerged C-F bands are advantageous when they react with lithium ion during discharge. The results show that Li/FMWCNT cells possess higher discharge potential than Li/GF cells.

Abstract: This paper presents a review of creep cavitation and rupture of low Cr alloy and its weldment, particular in the heat-affected zone (HAZ). Creep damage is one of the serious problems for the high temperature industry. One of the computational approaches is continuum damage mechanics which has been developed and applied complementary to the experimental approach and assists in the safe operation. However, the existing creep damage constitutive equations are not developed specifically for low stress. Therefore, in order to form the physical bases for the development of creep damage constitutive equation, it is necessary to critically review the creep cavitation and rupture characteristics of low Cr alloy and its weldment.