Title:Development of an Integrated System for the Automatic Viscosity Correction of a Ceramic Slurry for the Investment Casting Process
VOLUME: 12 ISSUE: 3
Author(s):Giovanni M. Carlomagno*
Affiliation:Department of Industrial Engineering, Aerospace Section - University of Naples Federico II Piazzale Tecchio 80, Napoli 80125
Keywords:Ceramic slurries, fluid dynamic drag, investment casting, slurry automatic correction, turbine blades production,
viscosity control.
Abstract: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.
