Multi-piece integrated core-shell structure for making cast component

Abstract

The present disclosure generally relates to partial integrated core-shell investment casting molds that can be assembled into complete molds. Each section of the partial mold may contain both a portion of a core and portion of a shell. Each section can then be assembled into a mold for casting of a metal part. The partial integrated core-shell investment casting molds and the complete molds may be provided with filament structures corresponding to cooling hole patterns on the surface of the turbine blade or the stator vane, which provides a leaching pathway for the core portion after metal casting. The invention also relates to core filaments that can be used to supplement the leaching pathway, for example in a core tip portion of the mold.

Description

INTRODUCTION[0001]The present disclosure generally relates to graded investment casting two piece core-shell mold components and processes utilizing these components. The two piece core-shell mold is assembled from a partial mold including a first core and shell portion. The two piece core-shell mold is assembled by attaching the first core and shell portion to at least a second core and shell portion of a second partial mold. The two piece core-shell mold made in accordance with the present invention may also include integrated ceramic filaments between the core and shell of the mold that can be utilized to form holes, i.e., effusion cooling holes, in the cast component made from these two-piece molds. The use of sufficient ceramic filaments between core and shell to both locate and provide leaching pathways for the core serpentine also enables the elimination of ball braze chutes. Ceramic filaments between the tip plenum core and the shell may also be provided to support a floatin...

AI Technical Summary

Benefits of technology

[0013]The large number of filaments used to form a cooling hole pattern may provide sufficient strength to support the tip core. If the tip filaments are made to support tip plenum core, they may be made larger, i.e., >2 mm cross section area, and a much lower number of filaments, or a single filament, could be used. Although two to four of these larger filaments is a desirable number. After casting, any holes or notches remaining in the tip plenum sidewalls as a result of the filaments may be brazed shut or incorporated into the turbine blade or stator vane design, or the filaments may be placed outside the finish machined shape of the component to prevent the need for this.

Problems solved by technology

Many modern engines and next generation turbine engines require components and parts having intricate and complex geometries, which require new types of materials and manufacturing techniques.

Conventional techniques for manufacturing engine parts and components involve the laborious process of investment or lost-wax casting.

However, these post-casting modifications are limited and given the ever increasing complexity of turbine engines and the recognized efficiencies of certain cooling circuits inside turbine blades, more complicated and intricate internal geometries are required.

While investment casting is capable of manufacturing these parts, positional precision and intricate internal geometries become more complex to manufacture using these conventional manufacturing processes.

The ceramic core-shell molds according to the '151 patent are limited by the printing resolution capabilities of these processes.

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