Papers by Keyword: Runner

Abstract: Selection of an appropriate gating system for a consumable pattern is a long and time-consuming process that requires considerable effort. Advanced design technologies can be used to design the gating system and to simulate the casting process based on the design. Simulation and design of the gating system allow detection of types of defects in the casting at the development stage. Parametrical changing of the gating system 3D model and variation of its characteristics, and repeated simulation of cooling, crystallization and mold filling processes can provide high quality casting.

Abstract: Semi-solid slurry has significantly higher viscosity than liquid metal. This character of fluidity makes product design and die design, such as gating system, overflow and venting system, be different between these two die casting processes. In the present paper, taking a clamp product as an example, analyses the product optimization and die design by comparing the experimental and computational numerical simulation results. For the clamp, product structure is designed to be suitable for characters of SSM die casting process. The gating system is designed to be uniform variation of thickness, making the cross-sectional area uniformly reduce from the biscuit to the gate. This design ensures semi-solid metal slurry to fill die cavity from thick wall to thin wall. Gate position is designed at the thickest location, the gate shape of semi-solid die casting is set to be much bigger than traditional liquid casting. A good filling behaviour can be achieved by aforementioned all these design principles and it will be helpful to the intensification of pressure feeding after filling.

Abstract: Thickness thinning repair analog simulated using fluid mechanics research tool ANSYS-CFX of mixed-flow turbine runner blade,Through the three-dimensional flow and numerical calculation and analysis of energy distribution on the blade after featheredging. Leaf blade repair thickness thinning after 0.5CM in the cavitation performance, vibration performance and operation performance of the performance indicators to achieve the ideal state, The new method for reducing wheel vibration, vortex row, There is a certain positive significance in improving the efficiency of turbine, make full use of new energy.

Abstract: The unibody of LED lampshade is the expansion of a lampshade array from single-LED in order to decrease assembly time, the forming technique is complicated. This study employ solid model to build micro mold, and find out the optimal design parameters, such as gate position, running system, cooling system and holding pressure system. The improvement of gate system can reach flowing equilibrium when molten plastic flows into cavity, and no welding line is produced. In the cooling stage, the cooling speed at each cavity is also steady and balance in order to reduce residual stress and lens defects. This study utilizes multi-gate system and multi-stage holding pressure aided forming to decrease welding line and residual stress. This study improves traditional mold design to fit more multi-cavity LED mold design which includes cooling system redesigning, cavities layout, flowing balance in runner and reducing shear stress. The Taguchi method and orthogonal array are used in the study for each group of experiment; many factors are applied to obtain the minimum shear stress, minimum warp, reduction of flow mark and uniform stress distribution. The results can provide for industry reference.

Abstract: The reasons are analyzed that propeller turbine cannot work properly under littler volume in some seasons, and then a scheme of capacity-decreasing improvement is put forward. Characteristics of design under hyper-normal factors are pointed out. Software of hydraulic design for lower specific speed axial flow runner blades has been developed by Visual Basic and AutoCAD basing on the method of singular point distribution. Finally, an example to demonstrate and explain its use is given in this paper.

Abstract: FEM analysis of flow field in nano-laminated coextrusion die is introduced. Nano-laminated coextrusion die is a new type of laminated composite generator which is based on the principle of the melt calculus. The distributions of pressure field and velocity vectors are obtained and analyzed. The result using finite element simulation software Polyflow shows an improvement in structure of die as well as better quality for melt flow characteristics. The paper is helpful in design and optimization of coextrusion die and process.

Abstract: Based on the soft of FLOW3D, the numerical simulation was study the effect of runner-reduction ratio on the dispersing uniformity of added powders inside alloy melt. The parameters studied were gating shape and reduction ratio in cross section area. The results revealed that dispersing uniformity of powders, the flat gating system is better than the comb one, and the best dispersing uniformity was achieved when the reduction ratio was up to 50%.

Abstract: The influence of the heat loss of hot runner on the stability of mold injecting process was analyzed. Determine the lost power of heating elements by establishing of hot runner system. Using ANSYS codes to calculate the temperature control equations and get the temperature distribution of hot runner plate. Make the structural arrangement of heating pipes and thermocouples better and ensure thermal equilibrium of the hot runner system by analyzing the temperature field.

Abstract: Due to its attractive characteristics, thin wall ductile iron (TWDI), has been increasingly considered as a preference for reducing material consumption in order to save energy and contribute less environment pollutions as well as decreasing costs. In this research, the effect of two mould runner gating systems and mould coating on graphite nodule characteristics and hardness values of TWDI casting was studied. Strip samples with various thicknesses of 2.3, 3.3, 4.5, 5.4, 6.5, 7.5 and 8.5 mm were casted into CO2 Silicate moulds designed by two gating systems namely stepped and tapered runners. Half of the moulds were coated by graphite-based zircon material to investigate the effect of mould coating on the graphite nodule qualities and quantities. The molten metal prepared contained carbon equivalent (CE) of 4.29% and was poured at the temperatures of 1450°C. Optical microscope (OM) and Clemex Image Analyzer (CIA) were used to evaluate graphite nodule count, roundness and diameter of the nodules of the TWDI cast samples. Brinell hardness test was performed on all samples. The results show that roundness and graphite nodule counts in the microstructure of the samples produced in stepped runner gating system and uncoated mould decrease whereas graphite nodules diameter shows opposite behaviour. Furthermore, molten metal experienced a superior fluidity in coated moulds. Moreover, the TWDI samples achieved a significant improvement in the value of hardness.

Abstract: Traditional gravity pour down-sprue methods of filling moulds in the making of aluminum castings inherently lead to oxide and air bubble entrainment. The reason for this is found in the high velocities the metal flow experiences during the filling of a mould. The Nemak Windsor Aluminum Plant (WAP) produces cylinder blocks using the low-pressure Cosworth process, which includes low velocity up-hill filling of the sand mould package. This doctrine is followed in all except one part of the process: the runner system. The nature of the resulting defect is generally known as Head Deck Porosity. Runners were cast full in open production runners at three different velocities with the resulting quickly chilled castings analyzed using X-ray radioscopy, and Scanning Electron Microscopy. Results reveal that the subject bubble porosity is indeed the result of air entrained during initial transient flow within the production runner system whose velocity is higher than the critical value of 0.5ms-1. This theoretical value is corroborated by experimental results. In addition, a new "sessile" runner of optimized shape, filled at a velocity slower than the critical value, is proposed and analyzed using Magmasoft mould fill modelling software. The design can potentially replace the existing runner providing a casting free of entrained air.