Papers by Keyword: Process Condition

Abstract: Internal cracks in 30Cr2Ni4MoV steel were produced by compressing cylindrical sample with drilled hole. In order to consider the effects of deformation degree, temperature, strain rate and holding time on the crack healing, the hot compression tests were performed on Gleeble-1500 thermo-simulation machine under different process conditions. By in situ observation under optical microscope and scanning electron microscope, effects of process condition on crack healing and the behaviours of crack healing were revealed successfully: (1) the result of crack healing improves as the melt temperature, reduction and holding time increase, (2) the effect of crack healing decreases as the strain rate increases. By the energy dispersive spectroscopy, it is also found that the chemical composition of the healed crack area is different from that of the matrix.

Abstract: Base on the discussion of the wood-plastic composite cushion packaging material progress at home and abroad, this article analyzes foaming mechanism, process conditions and methods on how to improve interface compatibility in preparing WPC material. Point out that bubble quality control during the foaming nucleation stage, the proportion of the compound blowing agent, process condition selection and interface modification are the Key issues in research of the WPC cushion packaging material.

Abstract: In order to analyze the influences of process condition on kerosene-based Fe₃O₄, which are prepared in chemical co-precipitation, orthogonal experiment was used. How process condition influenced the size of nano-particles and saturation magnetization was studied, and the best process condition as 40ml•min^-1 NaOH adding speed, 10ml•min^-1 sodium oleate adding speed, 45°C reaction temperature, 15min holding time and pH value of 2 of coating sodium oleate was obtained. The performance of magnetic particles was characterized by transmission electron microscopy (TEM) and WSM vibration magnetometer. The diameter of Fe₃O₄ nano-particles was less than 10nm, saturation magnetization was 2.66×10⁴A•m^-1, viscosity of nano-magnetic fluid was 18mPa•s, and density was 1.13×10³kg•m^-3. This research enhanced the foundation of using nano-magnetic fluid.

Abstract: In this work, one step for sensitization and activation in pretreatment process is adopted. The influences of the temperature, pH value on electroless Ni-P plating on PVC plastic were discussed. The components and surface morphology of the coating were studied by using SEM and EDS. The results show that the optimum operating condition is temperature being 50～55 , the optimum pH value being 8.5. Under the optimal technical conditions, the deposits is smooth and uniformity. The adhesion between the deposits and the matrix is better, The deposit contains 97.68% (wt) Ni and 2.32% (wt)P by the analyses of energy disperse X-ray.

Abstract: Magnesium alloy is the lightest metal that can be used as structural material at present. As a novel forming process for magnesium alloys, thixomolding can result in a product with few defects and superior dimensional accuracy, and it is suited to manufacture the thin wall products especially. In this paper, the samples of mobile phone housing were fabricated by 220Tons thixomolding machine made by Japan Steel Works. The effects of barrel temperature, screw rotate rate and injection velocity on the mechanical properties were studied. The relationship between process parameters and mechanical properties was investigated. The results show that the effects of barrel temperature and screw rotate rate on the mechanical properties can be divided to low temperature and high temperature stage. The high tensile strength are corresponding to the best injection velocity.

Abstract: The relations between interfacial properties of clad composite and process conditions are studied. Adherence on interface of two materials is most significant property of clad composite. Properties of composite material are manifestation of its microstructure, and process conditions are decisive factor to the microstructure in interfacial area. In-depth understanding about the composite’s properties is only achieved through appreciation of the mechanism by which the process conditions affect the microstructure. Aluminum and copper clad composite bars are extruded at the various process conditions. Interfacial adherence of the extruded composite is examined. Microstructure of the dispersed layer and its vicinity is investigated.