Papers by Keyword: Micropore

Abstract: The lightweight of refractory is propitious for energy-saving and emission-reduction of the high temperature refractories industry and sustainable development of the refractories resource. This paper researches on properties of the lightweight mullite aggregate which is prepared by two kinds of bauxites and aluminum dross and fired at 1400°C,1450°C,1500°C,1600°C for 1h. The result shows that, (1)The minimum density of grade Ⅰ bauxite is 2.11g/cm3 which is prepared by adding 50wt% aluminum dross and fired at 1600°C; (2)The minimum density of grade Ⅲ bauxite is 1.54g/cm3 which is prepared by adding 50wt% aluminum dross and fired at 1450°C.

Abstract: The paper studies micropore electric spark machining of Hymu 80 soft magnetic alloy materials focusing on the influence of gap voltage on the processing to commence the experiment and analyze experimental results. It also discusses the influence of gap voltage on electrode consumption length, the diameter difference of inlet and outlet and reaming amount, find the optimization matching between peak point current and gap voltage, and proposes the idea of improving micropore process.

Abstract: The effects of hot isostatic pressing on the microstructures of a third generation single crystal Ni-based superalloy DD10 were investigated by using optical microscope (OM), scanning electron microscope (SEM), electron microprobe analyzer (EPMA). The results showed that the micropores in the interdendritic region were eliminated completely after hot isostatic pressing at 1320 and 150MPa. Meanwhile, the morphology of γ precipitates changed to be more cuboidal and the distribution of γ precipitates in both dendrite core and interdendritic region became more uniform after hot isostatic pressing. Hot isostatic pressing also promoted the homogenization of the composition between dendrite core and interdendritic region and the dendritic segregation of Re, W, Al and Ta was decreased.

Abstract: To improve the efficiency of heat utilization on domestic gas-cooker, the reasons of low-heat efficiency and the factors which influence the measurement of heat efficiency were analyzed in this paper. A new energy-saving apparatus of domestic gas-cooker is developed by the preparation of special heat-insulating material, heat reflecting paint and the use of multilayer, scraggly and crossed abdominal fire rings. Meanwhile, the special designs with resort chambers of flame and the micropores can contribute to the circulation of combustion-supporting hot air. It has also demonstrated that the design increased evidently the detention and reflection of heat. Test results show that the efficiency of gas combustion and the heat utilization were effectively improved.

Abstract: The flaws in a heavy bridge-making steel plate (Q370qE) were detected by ultrasonic test, the types and formation reasons of which were studied by metallographic examination, scanning electron microscope (SEM) and energy dispersive X-ray (EDX) spectrometer. The results showed that the types of the flaws were mainly crack, micropore and inclusion. The formation of crack and micropore was attributed to the center segregation, porosity, as well as the role of structural stress and thermal stress. Moreover, the inclusions were mainly composite oxides (MgO, Al₂O₃, CaO, etc.) and MnS, the former came from the raw materials and impurity oxides, however, the latter came from the center segregation of the alloying elements. Besides, some improvement measures to reduce detecting flaws were also proposed.

Abstract: From the rheological theory, the combination of the rheological characteristic of melt spinning and principle of spinning, the paper researches the mathematical model of the velocity distribution and shear rate distribution when the melt flow in composite spinning sheath-core orifices. According to the mathematical model, the melt flow velocity and pressure characteristic of the composite spinning micropore are researched with the software of CFD-Fluent. The results for the design of composite spinning technology and components provide a good theoretical basis.