Advanced Materials Research Vols. 941-944

Abstract: The high speed milling test of CVD composite coated tool cutting natural marble is carried out. Measured milling forces of different parameters by the dynamometer and analyzed the influence of different parameters on the cutting force. Observed the wear appearance by the SEM and analyzed the wear mechanism of CVD tool. The results of the experiment show that the cutting force increases along with the cutting depth and feed speed increase, decreases along with the spindle speed and the influence of the cutting depth is the largest. The wear mechanisms of CVD tool when milling the natural marble include the removal of mechanical loss on the tool substrate, oxidation wear and adhesion wear. The removal of mechanical loss and adhesion wear couple with the whole process of CVD composite coated tool.

Abstract: The present work investigated the effect of laser surface melting (LSM) process on micro arc oxidation (MAO) coating prepared in silicate electrolytes (Si-MAO) and aluminate electrolytes (Al-MAO). Plasma intensity of laser spots, element content and phase constituents of coatings were analyzed. During LSM remelting process, the formation of heat sources and micro molten pools on the surface of MAO coating were discussed. The results showed that the moderate plasma was formed more easily on the Si-MAO than Al-MAO coating, owing to the temperature threshold of melting oxide layer was decreased for silicon-containing MAO coating during LSM treatment. Besides, the Si-MAO coating of laser-treated had low porosity and smooth surface.

Abstract: In this study, the influence of sodium dodecylbenzenesulfonate (SDBS) as additive on the morphology and nucleation mechanism for zinc electrodeposition on steel sheet was investigated using scanning electron microscopy (SEM) and potentiostatic electrochemical techniques. From the analysis of the chronoamperometric transients and the SEM images, an instantaneous nucleation with 3D growth has been proposed in both baths with and without SDBS. It was found that the morphology of zinc electrodeposits varied from initial thin-layered hexagonal plates to a finer ridge and needle morphologies with increasing the overpotential as SDBS was added in the bath solution.

Abstract: Antibacterial layer was prepared on the aluminum surface by anodizing pure Al and electrodepositing Cu in the pores of the anodic aluminum oxide (AAO) membrane. The AAO membrane was generated by a two-step anodization process in oxalic acid solution. The electrodeposition of Cu was conducted in copper sulfate solution using alternating current. The structural characterizations by scanning electron microscopy (SEM), X-ray diffractometer (XRD) and energy-dispersive spectrometer (EDS) show that Cu nanowires with an average diameter of 70 nm are assembled in the pores of the AAO membrane. The tests of antimicrobial properties against two typical bacteria of Escherichia coli (E. Coli) and Staphylococcus aureus (S. Aureus) indicate that surface antibacterial layer of aluminum possesses excellent antimicrobial properties and the maximum value of the antibacterial rate can reach 99.9% both for E. coli and S. aureus.

Abstract: Wire breaking is a major factor in the impact of wire drawing production, and drawing process is an important factor causing the wire breaking, which cannot be ignored. In this paper, the impact of tension, bending stresses, centrifugal stresses, compression ratio of die arrangement and drawing speed in the process of the wire drawing process on wire breaking were calculated theoretically. Then the corresponding measurements to reduce the rate of wire breaking were proposed. The results show that the the tension of drawing process was the main factor, while choosing the right compression ratio and drawing speed according to the actual situation, the rate of wire breaking could be reduced effectively.

Abstract: The influences of parameters on fine blanking of steel synchronizer ring teeth have been studied in this paper. Based on the finite element (FE) analysis software DEFORM-3D, a three-dimensional FE model of fine blanking of steel synchronizer ring teeth was established. By analyzing the distribution of hydrostatic stress, the length of smooth cut surface and the height of die-roll, the influence of parameters (i.e., counterforce, blanking clearance and V-ring indenter form) on the cut surface of synchronizer ring teeth were discussed. The quantitative relationships between parameters and the cut surfaces were established. The results show that: Increasing counterforce, decreasing blanking clearance and V-ring indenter located on die are conducive to increase the length of smooth cut surface and to decrease the height of die-roll. These results have a certain guiding significance on the production process of fine blanking of steel synchronizer ring.

Abstract: Filling unbalance is a critical defect for injection mould. When the upper and lower covers of soap plastic box are produced by injection mold at the same time, filling unbalance in injection would appear because of the different dimensions of the two parts. For advancing the quality of the soap plastic box, the runner system is optimized with the filling analysis module and flow runner balance module of moldflow simulation software. The three-dimensional geometrical models of the two covers are constructed using Pro/e software. In moldflow the runner balance optimization of the soap box compounding cavity is analysis. The results indicate the optimized cross section of the runners can reduce the flow unbalance ratio from 3.38% to 0.73%, and the filling time and pressure can satisfy the demands. According to the analysis results moldflow is appropriate for runner balance design of the plastic products.

Abstract: Based on the FEM software simufact.forming, a finite element model of the radial-axial ring rolling for one ring product was constructed and the rolling process under different drum-shaped blanks were simulated in this paper, which revealed the variation of drum-shaped blank in the rolling process, analyzed the formation process and further proposed measures of eliminating collapse defect. The results show that the drum disappearing rate in initial rolling stage is greater than in later stage and it becomes increasingly difficult to disappear, which leads to collapse defect in the end. The drum-shape can be reduced by greater radial feed in initial rolling stage in the case of small drum-shape or rounding before rolling on ring rolling machine in the case of large drum-shape for avoiding collapse defect. The results provide valuable guiding significance for practical production.

Abstract: This study is aimed to investigate the spring-back angle of clad metal sheet in bending process by using finite element simulation and experiment to meet the growing requires in the application of clad metals. In this study, the clad metals processed into 1mm thick from CU11000 and AL1050 were bent 90o over a die with a bend radius of 1mm. The results show that there is not any relative sliding, crushing or peeling occurred in the junction of the clad material during the bending process, the spring-back angle of the clad metal is always smaller than each single metal and the CU content increasing also caused spring-back angle become small. The configuration of a harder material (CU11000) in tensile side also has a smaller spring-back angle.

Abstract: For large forging is high-tech product of material, smelting, forging, heat treatment and it is the bottleneck which restricts the development of the modern heavy equipment manufacturing industry. The key technology such as forging and heat treatment of large forgings is researched. Finally, with the ultra supercritical power generation units of low-pressure rotor, the production process control technology such as smelting, forging and heat treatment is introduced. The method provides a reliable basis for the localization of production of ultra supercritical steam turbine rotor and has the important practical application value.