58796 - 3d Printing of Ceramic Shell Molds for Precision Casting of Turbine Blades
Traditionally, the technology used in the production of gas turbine blade castings characterized by a large number of technological conversions, high labor costs with a large amount of manual labor and the need to produce various types of complex and expensive equipment at different stages of production. This technology is designed for large runs and mass production and uses expensive molds.
This work aims to reduce the time and money spent on the manufacturing of ceramic shell shapes - a form suitable for the standard methods of precision casting by traditional heat-resistant nickel alloys.
The proposed approached involves obtaining a shell shape with an internal rod as a single, non-assembled product, without lengthy and time-consuming design and manufacturing processes involved in forming equipment for the production of castings based on smelted models. In this way, all production processes for manufacturing foundry equipment are integrated into a single technological process that eliminates all intermediate operations due to special approaches in the design of the elements and the use of three-dimensional printing with ceramic materials for production.
The proposed method is based on the use of 3D printing with refractory ceramic pastes. When designing the technological process for manufacturing ceramic shell shapes, a number of problems related to their porosity and strength were solved. There was an due need for resistance to cracks during heat exchange, pouring with a liquid metal melt, and subsequent cooling during the passage of the shell mold with a liquid metal of the crystallization front through the temperature gradient zone at the interface between the melt and solid metal.
Ceramic samples were made and their characteristics determined to test the physical, chemical, and mechanical properties of the printed forms.
Using both uncooled and cooled blades as examples, models of casting molds were designed, technological processes were developed, and ceramic shell molds were manufactured. Non-destructive testing on a computer tomograph was done in order to control geometric deviations of internal cavities and detect flaws in manufactured shell forms.
Experimental casting into a manufactured ceramic shell mold for an uncooled blade with a bandage shelf was performed and showed satisfactory results.
An approximate analysis of the economic and time factors of tooling manufacturing was also carried out. When printing three castings of cooled blades, 3D printing is 13.5 times more profitable than the traditional method of manufacturing the shell for casting a cooled blade, and the production time is reduced by almost six times.
With this approach, manual labor is practically eliminated and production is carried out automatically. The mold design allows the production of various types of blades, including blades with internal cooling channels. This method completely removes the lengthy processes of designing and manufacturing model tooling (model molds) and significantly reduces the time and cost of manufacturing prototype castings. This approach is also focused on flexible small-scale production, so it is ideal for quickly obtaining products in order to test their properties at the R&D stage.
3d Printing of Ceramic Shell Molds for Precision Casting of Turbine Blades
Paper Type
Technical Paper Publication
Description
Session: 18-05 Digitization, Testing and Validation
Paper Number: 58796
Start Time: June 11th, 2021, 02:15 PM
Presenting Author: Liubov Magerramova
Authors: Boris Kozlov Arcon, LLC, CEO
Eugene Kratt LNT, LLC, CEO
Liubov Magerramova Central Institute of Aviation Motors