Development of an Integrated System for the Automatic Viscosity Correction of a Ceramic Slurry for the Investment Casting Process

2019 ◽  
Vol 12 (3) ◽  
pp. 211-219
Author(s):  
Giovanni M. Carlomagno
Keyword(s):  
Investment Casting ◽  
Casting Process ◽  
Experimental Tests ◽  
Integrated System ◽  
Layer By Layer ◽  
Automatic Correction ◽  
Ceramic Slurry ◽  
Transducer Output ◽  
Slurry Viscosity ◽  
Cast Parts

Background: Starting from a wax model of the mold, which is later discarded, investment casting is used to make almost finished metal cast parts. The term "investment casting" is derived from the use of a ceramic liquid mixture (slurry), in which the model is repeatedly immersed (invested) to form, layer by layer, the shell which has to be filled with molten metal. The liquid of the slurry tends to evaporate so that the viscosity of the former increases and a correction is needed. Objective: The study aimed to investigate the simplest way to measure slurry viscosity and automatically correct it. Methods: Numerical and experimental tests have been implemented to correctly assess the proposed method. An integrated system for the automatic correction of slurry viscosity is realised which comprises: a reservoir of slurry including means for mixing it; a transducer which continuously measures the slurry viscosity; a pump that gradually feeds the diluent into the slurry to keep its viscosity constant; and a device, governed by the continuous viscosity measurement, that operates the pump. Results: It has been proved that the developed system is able to integrate the slurry viscosity continuous measurement with gradual addition of diluent into the slurry, so as to have a fully automated operation that can make corrections, whenever necessary, on the basis of the transducer output. Conclusion: The developed system works properly by keeping the slurry viscosity within a fixed range. A patent has been recently deposited to protect the integrated system for the automatic correction of slurry viscosity.

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

Investment Cast Biomedical Implants From Rapid Prototyping and Tooling Techniques

2000 ◽  
Author(s):  
K. P. Walsh ◽  
D. G. Boyle ◽  
D. I. Wimpenny
Keyword(s):  
Rapid Prototyping ◽  
Investment Casting ◽  
Casting Process ◽  
Lead Times ◽  
Biomedical Implants ◽  
Contributing Factors ◽  
Investment Cast ◽  
Wax Pattern ◽  
Prosthetic Implant ◽  
To Receive

Abstract Traditionally investment casting of biomedical implants has utilized the lost wax process, this paper is an investigation into the possibilities of casting small lots of custom specific medical implants directly and indirectly from various rapid prototyping & tooling techniques. Small batch quantities for quick turn arounds cost and lead times are the main contributing factors for the purpose of this investigation. To directly produce parts means that a RP model will be used in the place of the wax pattern in the investment casting process. To indirectly produce parts means that a mould, which has been generated from RP&T techniques, will be used to manufacture wax patterns that will then in turn be used to investment cast the parts. The device to be manufactured is a non-sterile, referred to as ‘trial’ prosthetic implant. The implant is used by the operating surgeon to check the ‘fit’ of the cavity that will be made to receive the prosthesis plus bone cement that will be used to fix the implant in place.

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