Foundry Ceramic Core Tooling for Turbomachine Vanes
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing lost-wax casting techniques for manufacturing metal blades with complex internal cavities, particularly in gas turbine engines, face challenges with premature tool wear and deformation due to increased shearing stresses and infiltration of ceramic pastes, leading to production stoppages, maintenance costs, and defects such as cracks and burrs in the core.
Innovation Solution
A modified mold design where certain movable zones are fixed, and mechanical ejectors are used to extract the core with distributed low-pressure contact points, ensuring parallel stripping and minimizing deformation, combined with a ceramic core composition of 80-85% mineral filler and 15-20% organic binder for improved handling and machining.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If injection flow rates or pressures are increased to fill mold cavities, then filling quality improves, but tool wear increases due to shearing stresses
Solution Approach 1:
The mold is divided into two separable cavities (first cavity and second cavity) that can move relative to each other. This segmentation allows the ceramic paste to be injected and then the cavities to separate, reducing shearing stresses on the paste and preventing tool wear while maintaining filling quality.
Solution Approach 2:
The mold cavities are designed to be movable rather than fixed. The first and second cavities can translate between open and closed positions, dynamically adapting during the injection and stripping processes. This dynamic design reduces resistance to paste flow and minimizes wear on tooling.
2Manufacturing precision
If ceramic paste infiltration occurs during filling, then filling completeness improves, but core deformation occurs during stripping
Solution Approach 1:
The mold is segmented into movable cavities that can separate after injection. This allows the ceramic paste to infiltrate and fill the mold completely during the closed position, then the cavities separate to allow stripping without deforming the core, as the paste is not constrained by fixed mold walls during extraction.
Solution Approach 2:
The ceramic paste is injected and allowed to infiltrate and set before the stripping operation begins. The preliminary injection and setting action ensures complete filling, then the movable cavities are opened to perform stripping without causing deformation, separating these actions in time.
3Ease of operation
If movable zones in the mold are used, then ease of stripping improves, but core deformation increases due to infiltration
Solution Approach 1:
The mold is divided into separable cavities that provide ease of stripping while controlling paste infiltration. The segmented design allows each cavity to move independently, facilitating stripping without the paste infiltrating into fixed mechanisms, thus preventing deformation while maintaining ease of operation.
Data Source
Figure 1~2
Figure 3
Figure 4~5
AI summary
The present invention relates to a tooling for manufacturing a foundry core, for a turbomachine blade with a leading edge and a trailing edge, the core (10) comprising a thick part on the leading edge side and a thin part (10A1) on the trailing edge side, comprising a first and a second core cavity (530, 540) movable in a direction (F'1 respectively F'2) relative to each other between a molding position and a demolding position, with optionally sub-parts movable relative to the cavities, characterized in that the cavity parts corresponding to said thin part of the core do not include a movable sub-part, mechanical ejectors (570) being provided on one or the other of the cavities, such that the thin part (10A1) of the core is demolded along the main opening direction.