scholarly journals Dimensionless analysis for modelling surface finish in conventional investment casting

2016 ◽  
Vol 45 (2) ◽  
pp. 123-129 ◽  
Author(s):  
Rupinder Singh ◽  
Sunpreet Singh
Keyword(s):  
Mathematical Model ◽  
Surface Finish ◽  
Investment Casting ◽  
Casting Process ◽  
Dimensionless Analysis ◽  
Slurry Layer ◽  
High Level ◽  
Main Effects ◽  
Shed Light ◽  
Study Application

High level surface finish (SF) achievement is one of the major advantages of conventional investment casting process. Not much work hitherto has been reported for modeling the SF in conventional investment casting of industrial components. In the present study application of dimensionless analysis, has been made for developing a mathematical model for SF. Three input process parameters (namely: molten metal pouring temperature (PT), slurry layer’s combination (LC) and volume/surface-area (V/A) ratio of cast components) were judicially selected to give SF as output. This study provide main effects of these input parameters on SFand shed light on the SF mechanism in conventional investment casting. The comparison of mathematical model with experimental results has been made for validation of model.

scholarly journals Evaluation and optimisation of a slurry-based layer casting process in additive manufacturing using multiphase simulations and spatial reconstruction

2021 ◽  
Author(s):  
P. Erhard ◽  
A. Seidel ◽  
J. Vogt ◽  
W. Volk ◽  
D. Günther
Keyword(s):  
Surface Roughness ◽  
3D Printing ◽  
Fine Particles ◽  
High Surface ◽  
Casting Process ◽  
Spatial Reconstruction ◽  
Novel Method ◽  
Slurry Layer ◽  
High Level

AbstractSlurry-based 3D printing allows ceramic green bodies to be fabricated at high packing densities. In contrast to powder-based binder jetting, full densification of printed parts can be achieved in a subsequent sintering step as fine particles dispersed in a suspension are cast and compacted. Slurry-based 3D printing is thus expected to overcome the application limits of the powder-based alternative in metal casting in terms of unfavorable properties like high surface roughness, low density and low mechanical strength. To ensure stress-free drying and therefore high qualities of the compounds made in layers, it is crucial to fabricate single layers with a high level of homogeneity. This paper presents a CFD model based on the open-source simulation environment OpenFOAM to predict the resulting homogeneity of a cast slurry layer with defined parameter sets or coater geometries using the Volume-Of-Fluid method. Moreover, a novel method of spatial reconstruction is proposed to evaluate the surface quality of layers on a minimised computional demand. By comparing the results of the simulation with the real macroscopic behaviour determined in experiments, the approach is found to be a useful tool for suggesting suitable parameters and coater geometries for processing slurries. A precise reconstruction of the outline of the coating area with different process parameters and an approximate prediction of the effect on surface roughness was achieved.

scholarly journals FEM Simulations for the Optimization of the Inlet Gate System in Rapid Investment Casting Process for the Realization of Heat Exchangers

2021 ◽  
Author(s):  
D. Almonti ◽  
G. Baiocco ◽  
E. Mingione ◽  
N. Ucciardello
Keyword(s):  
Investment Casting ◽  
Heat Exchangers ◽  
Complex Geometry ◽  
Heat Pipes ◽  
Casting Process ◽  
Added Value ◽  
Cad Models ◽  
Gate System ◽  
Definition Of ◽  
Metallic Parts

AbstractOver the last decades, additive manufacturing (AM) has become the principal production technology for prototypes and components with high added value. In the production of metallic parts, AM allows producing complex geometry with a single process. Also, AM admits a joining of elements that could not be realized with traditional methods. In addition, AM allows the manufacturing of components that could not be realized using other types of processes like reticular structures in heat exchangers. A solid mold investment casting that uses printed patterns overcomes typical limitations of additive processes such as expensive machinery and challenging process parameter settings. Indeed, rapid investment casting provides for a foundry epoxy pattern reproducing the component to exploit in the lost wax casting process. In this paper, aluminium radiators with flat heat pipes seamlessly connected with a cellular structure were conceived and produced. This paper aims at defining and investigating the principal foundry parameters to achieve a defect-free heat exchanger. For this purpose, different device CAD models were designed, considering four pipes’ thickness and length. Finite element method numerical simulations were performed to optimize the design of the casting process. Three different gate configurations were investigated for each length. The numerical investigations led to the definition of a castability range depending on flat heat pipes geometry and casting parameters. The optimal gate configuration was applied in the realization of AM patterns and casting processes

scholarly journals Dimensionless Analysis on the Characteristics of Pneumatic Booster Valve with Energy Recovery

2016 ◽  
Vol 2016 ◽  
pp. 1-13
Author(s):  
Fan Yang ◽  
Kotaro Tadano ◽  
Gangyan Li ◽  
Toshiharu Kagawa
Keyword(s):  
Mathematical Model ◽  
Energy Efficiency ◽  
Energy Recovery ◽  
Operational Parameters ◽  
Local Pressure ◽  
Air Power ◽  
Improve Energy Efficiency ◽  
Dimensionless Analysis ◽  
Air Supply ◽  
Save Energy

Factories are increasingly reducing their air supply pressures in order to save energy. Hence, there is a growing demand for pneumatic booster valves to overcome the local pressure deficits in modern pneumatic systems. To further improve energy efficiency, a new type of booster valve with energy recovery (BVER) is proposed. The BVER principle is presented in detail, and a dimensionless mathematical model is established based on flow rate, gas state, and energy conservation. The mathematics model was transformed into a dimensionless model by accurately selecting the reference values. Subsequently the dimensionless characteristics of BVER were found. BVER energy efficiency is calculated based on air power. The boost ratio is found to be mainly affected by the operational parameters. Among the structural ones, the recovery/boost chamber area ratio and the sonic conductance of the chambers are the most influential. The boost ratio improves by 15%–25% compared to that of a booster valve without an energy recovery chamber. The efficiency increases by 5%–10% depending on the supply pressure. A mathematical model is validated by experiment, and this research provides a reference for booster valve optimisation and energy saving.

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