Multi-Directional Infiltration of Porous CMC Preforms
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Solution Overview
Problem
Conventional densification methods for ceramic matrix composite (CMC) articles in turbine engines often result in obstructions, cracks, and reduced material areas, exacerbating weaknesses, especially in thicker components, due to operational parameters that can damage the CMCs.
Innovation Solution
A method and system involving a die set with multiple molten densifier supply conduits flowing molten densifier in distinct directions, including one parallel to the unidirectional material orientation of ply stacks, to infiltrate and densify porous CMC preforms effectively, reducing the likelihood of defects and improving material density.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If conventional densification methods are used on CMC articles, then material density is improved, but defects such as obstructions, cracks, and reduced material areas are created
Solution Approach 1:
The patent changes the operational parameters of the densification process by using lower pressure and temperature conditions compared to conventional methods. This allows densification to proceed without exceeding the damage thresholds of CMC materials, thereby achieving improved density while maintaining structural integrity and avoiding defects like cracks and obstructions
Solution Approach 2:
The patent employs a multi-directional infiltration approach where molten densifier is introduced from multiple directions simultaneously. This dynamic infiltration strategy ensures uniform penetration throughout the CMC preform, preventing localized defects and achieving consistent density improvement without creating structural weaknesses
2Quantity of substance
If conventional densification methods are used on thicker CMC articles, then material density is improved, but weaknesses are exacerbated
Solution Approach 1:
The patent segments the densification process into multiple directional infiltration stages. By introducing molten densifier from multiple directions rather than a single source, the process ensures uniform penetration throughout thick CMC articles, preventing localized weak spots and achieving consistent density improvement without exacerbating structural weaknesses
Solution Approach 2:
The patent modifies the densification parameters to use lower pressure and temperature conditions that are suitable for thick CMC articles. This prevents thermal and mechanical stresses from creating or exacerbating weaknesses during densification, while still achieving the desired density improvement throughout the entire article thickness
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach enhances the density and operational efficiency of CMC articles by efficiently filling voids and reducing the size and number of reduced-infiltration areas, thereby increasing the operational life and reducing potential defects.
Implementation Method 1
flowing a molten densifier over the porous CMC preform in a first flow direction to infiltrate the plurality of voids formed between each of the plurality of ply stacks of the CMC preform; and flowing the molten densifier over the porous CMC preform in a second flow direction
Data Source
AI summary
Systems and methods for infiltrating porous ceramic matrix composite (CMC) preforms to form CMC articles are disclosed. One method may include positioning the porous CMC preform in an opening of a die set for an infiltration system, and flowing a molten densifier over the porous CMC preform in a first flow direction to infiltrate a plurality of voids formed between each of a plurality of ply stacks of the CMC preform. The method may also include flowing the molten densifier over the porous CMC preform in a second flow direction, distinct from the first flow direction, to infiltrate the plurality of voids formed between each of the plurality of ply stacks of the CMC preform. The second flow direction may be substantially parallel to a predetermined, unidirectional material orientation of at least one ply stack of the plurality of ply stacks of the CMC preform.