Advanced Materials Research Vols. 148-149

Abstract: A mathematical model for thermal transfer and solidification of beam blank casting has been established, which is solved by FEM. A dynamic secondary cooling control model is developed accordingly, and it can meet the need of online calculation for the entire temperature field of the beam blank casting, in which the amount of water for secondary cooling is set up and optimized by using effective casting speed and target surface temperature strategy. The dynamic secondary cooling control system is programmed by using Visual C++ 6.0 with friendly operation interface, which can be adopted not only for the online cooling control of beam blank casting but possibly for lab calculation of water table as well.

Abstract: A new kind of high temperature solid lubricant coating was synthesized by adopting new technique and using graphite, MoS2, Sb2O3 and Al2O3. Its tribological behaviors and lubricate mechanism were studied by means of wear testers. The experiment results show that the friction coefficient of the solid lubricant coating decreases with the increase of load and slightly increases with the raise of temperature. The solid lubricant coating still has good lubrication in 400 .

Abstract: In order to investigate effect of equal channel angular extrusion (ECAE) on microstructure and mechanical properties of annealed and solution-aged 6061 aluminum alloys, continuous ECAE process was carried out by physical test and finite element methods. The results show that the grains are refined with the increase of deformation; the metal flow lines cross and shear each other to form the clear boundaries. The solution-aged Al alloy does not show a monotonic increase in surface hardness with increasing passes as the annealed Al alloy does, but reaches a maximum value after the second pass and decreases successively during next two passes, which is closely related with the dislocation multiplication, recombination and annihilation. For the annealed and solution-aged Al-6061, the peak load reaches a maximum value in the second pass and fluctuates during the additional passes, which is caused by both material properties and frictions. The simulation shows that the peak load increases slowly with increasing passes, which is not in agreement with the measured value. Therefore the finite element mode using a single constitutive equation is not suitable for simulating multi-pass ECAE processing. The constitutive relations need to amend accordingly due to great changes of the mechanical properties between different passes.

Abstract: Since it is often appeared that connected-mold bearing FC208 rupture of roller foam machine in the production progress of a domestic company. A newly solve project on rupture of connected-mold bearing of roller foam machine based on finite element (FE) theory is put forward. All campaign process of this kind of machine is carried on mechanical analysis, and the maximum load force of bearing is calculated. FE models of FC208 and FC209 bearing are set up using ABAQUS software. The related simulation and analysis are conducted and force conditions of both components are compared with. The result of stress value is FC209 bearing is less than FC208 bearing. FC209 bearing is used in seven-positions rotating equipment made by ourselves in the company's No.40 # shop. The self-made equipment is running steady and reasonability of the improved design is proved.

Abstract: Laser bending process of tubes is a new flexible forming process without rigid tools and external forces. The tube is formed by internal thermal stress induced by laser irradiation. The process simulation of laser bending of tubes is realized numerically. When the other parameters remain invariable, the laser bending angle augments with the increase of the laser power. The laser bending angle decreases with the increase of the scanning velocity. Meanwhile, the bending angle varies with the diameter of the laser spot. The angle begins to decrease when the laser spot diameter get to an optimum value. The bending angle enlarges if the scanning wrap angle augments. The bending angle is largest when the scanning wrap angle is 180°. When the scanning wrap angle is over 180°, the bending angle decreases with the increase of the scanning wrap angle. The relationship between the number of scans and the bending angle is about in direct ratio. The bending angle induced by the first irradiated time is the largest.

Abstract: This paper presents a continuous modeling approach for multi-product re-entrant manufacturing systems. First, a generic continuous model for single-product re-entrant manufacturing systems is elaborated. Second, the concept of re-entrant factor is introduced to the model, which considers the influences of the re-entrant degree. Then, the continuous model is extended from single-product re-entrant manufacturing systems to multi-product re-entrant manufacturing systems in which the product priority is also taken into consideration. Finally, the proposed continuous model is validated through the Mini-Fab case study.

Abstract: The purpose of this paper was the optimization design of heavy strength carriage for 50t heavy-duty truck. Two optimization schemes B and C were provided based on original scheme A, which have different thickness of sole/side plate and main longitudinal girder and different number of strengthening ribs. ANSYS was used to do the finite element analysis of equivalent stress and elastic displacement of truck carriages. The equivalent stress of main longitudinal girder, soleplate and transverse bars of soleplate will increase when the soleplate’s thickness was reduced. The maximum of equivalent stress will increase 13%~15% with 1mm reduction. When the thickness of side plate or the number of side plate’s strengthening ribs was reduced, the elastic displacement of side plate would increase. Scheme C fulfilled the requirement of structure strength, in which the elastic displacement increases in the allowable range and the lightening ratio was 12.6%. Scheme B didn’t fulfill the requirement of structure strength. The numerical results provided theoretical foundations for optimization design of carriage in actual production and the solutions of expansion of carriage.

Abstract: Laser transformation hardening was carried out by HL-1500 CO2 laser on 40Cr steel. The macroscopic and properties were analysised by scanning electron microscope, X-ray diffractometer, microhardness meter and potentiostat. The result indicated that, the hardening layer is mainly constitute by Fe-Cr, C0.09Fe1.91, Fe2Si. After laser transformation hardening the hardness enhanced greatly, the maximum of hardness appears in the subsurface, which value is as about four times as that of the substrate, both wear resistance and corrosion resistance are improved. With the increase of the laser incident angle, microstructure’s inhomogeneity becomes larger, properties become decreased.

Abstract: Nowadays a general platform has played an important role in the product design process. As the traditional similarity measure used in module division is to the design stage in which the features and set are static, it is impossible to find the similar components in alterative design stages. For this reason, a new common platform design method on extension-distance is presented. According to build the relative function, the threshold used in the key module identification is easy to generate. Then the tolerance-constraint functions in the customized components division for the common platform generation. Then the adaptability measure is used to find the optimal case in the database. The measure has been used in the gasoline saw common platform design process.

Abstract: In order to explore the cutting rules of the 43-inch vane material --1Cr12Ni3Mo2VNbN on the turbine vane, and research the stress in cutting area, the strain as well as the temperature distribution and the variation, providing the reference data for the large-scale vane-root milling cutter's geometric parameter design and the cutting parameter optimization, the authors employed ANSYS / LS-DYNA finite element method to simulate and research the cutting process of the vane material. The authors adopted the two-dimensional plane element 2D SOLID l62 of the single-point integration Lagrange algorithm to establish the finite element cutting model, and established the Cowper-Symonds constitutive models based on the vane material, applied the 2D-r adaptive meshing to simulate the separation of the chip and workpiece. Obtain the distribution and rules of the stress, the strain as well as the temperature in the cutting area, and greatly shorten the period of the vane root milling cutter’s designing and trial-production.