National University of Science and Technology MISIS, Moscow, Russia.

A. A. Nikitina, Assistant at the Department of Casting and Material Working, e-mail: nikitina.misis@gmail.com
V. E. Bazhenov, Associate Professor at the Department of Casting and Material Working, Candidate of Technical Sciences, e-mail: v.e.bagenov@gmail.com
A. V. Koltygin, Associate Professor at the Department of Casting and Material Working, Candidate of Technical Sciences, e-mail: misistlp@mail.ru
V. D. Belov, Head of the Department of Casting and Material Working, Doctor of Technical Sciences, e-mail: vdbelov@mail.ru

Stability of process parameters is essential for obtaining good quality castings. Even that the ranges of permissible values of such parameters as casting and mould temperature or transfer time are quite wide, the final castings belonging to different batches may have differing quality. This paper analyzes some temperature-time parameters of the investment casting process to make cast bodies. The effect of the above mentioned parameters on the product quality was established. For this, computer simulation was carried out for the pouring and solidification of large thin-wall castings of nickel superalloy VZhL14N-VI cast in shell ceramic moulds. The simulation data show that a criterion for judging the quality of a casting includes the volume of shrinkage porosity in the casting. The authors analyzed a combined effect of the simulation parameters on the cooling rate of the casting wall. Thus, the authors give a number of recommendations on casting process optimization for obtaining castings as per specification. It was found that the difference between the pouring temperature and the mould temperature that ensured the casting cooling rate in the alloy freezing range of at least 2 oC/sec had translated into the best quality castings. Any further increase in the casting cooling rate does not influence the porosity.
This research was funded by the Ministry of Science and Higher Education of the Russian Federation following Governmental Decree No. 218 under Subsidy Agreement No. 075-11-2022-023 dated 6 April 2022: Developing a Process for Making Unique Large Superalloy Castings for Gas Turbine Engines with the Focus on Using Domestically Made Equipment and Setting Up Modern, Sustainable and Computer-Oriented Foundries.

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