Ceramic Matrix Composite Infiltration for Density and Porosity Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for manufacturing oxide ceramic matrix composites (CMCs) are time-consuming and challenging, especially for complex geometries, due to issues with slurry infiltration, drapability, and achieving uniform density and porosity, often requiring additional machining and multiple processing steps.
Innovation Solution
A method involving slurry infiltration with a solvent and matrix binder, where the solvent is partially removed by exploiting boiling point differences, allowing control over density, porosity, and fiber volume fraction without fully curing the binder, followed by repeated infiltrations until desired characteristics are achieved.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If traditional slurry infiltration methods are used with high solids content, then infiltration efficiency is improved, but control over density and porosity deteriorates
Solution Approach 1:
The infiltration process is segmented into multiple sequential steps with progressively decreasing solids content (75% → 50% → 25%). Each infiltration cycle targets specific porosity reduction needs, allowing precise control over final density and porosity characteristics while maintaining high overall infiltration efficiency
Solution Approach 2:
The solids content parameter of the slurry is systematically changed across infiltration cycles (from 75% to 50% to 25%). This parameter progression enables optimal infiltration rate in early cycles followed by precise porosity control in later cycles, resolving the contradiction between infiltration efficiency and manufacturing precision
2Manufacturing precision
If multiple infiltration cycles are performed to achieve desired density, then manufacturing precision is improved, but processing time increases
Solution Approach 1:
The preform is preliminary prepared with optimized fiber architecture and initial porosity distribution before infiltration begins. This preliminary structuring enables more uniform and faster infiltration in subsequent cycles, reducing total processing time while maintaining density uniformity
Solution Approach 2:
The infiltration process maintains continuous useful action by using overlapping infiltration cycles where each cycle builds upon the previous one. The progressive reduction in solids content ensures continuous porosity reduction without idle time, achieving density uniformity efficiently
3Adaptability or versatility
If complex geometries are manufactured using traditional methods, then adaptability is improved, but manufacturing complexity increases
Solution Approach 1:
The complex geometry manufacturing process is segmented into standardized infiltration cycles with consistent procedures. Each cycle follows the same pattern of slurry application, drying, and densification, simplifying the overall process complexity while maintaining adaptability to complex geometries through iterative application
4Quantity of substance
If high solids content slurry is used for infiltration, then porosity reduction is improved, but infiltration uniformity deteriorates
Solution Approach 1:
Different solids content slurries are applied to different stages of infiltration based on local needs. High solids content (75%) is used initially where rapid porosity reduction is needed, followed by lower solids content (50%, 25%) as infiltration progresses and uniformity becomes the priority, achieving both high matrix material content and infiltration uniformity
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
Enables efficient production of CMCs with improved control over density, porosity, and fiber volume fraction, reducing processing time and minimizing human errors, while maintaining complex geometries without additional machining.
Implementation Method 1
At least some of the solvent is removed by exploiting a difference in boiling point temperature between the solvent and the matrix binder. The preform is heated to a temperature greater than the boiling point of the solvent and less than the matrix binder to evaporate the solvent
Implementation Method 2
At least some of the solvent is removed by exploiting a difference in boiling point temperature between the solvent and the matrix binder
Data Source
Figure 1
Figure 2
Figure 3
AI summary
Disclosed is a method for making a ceramic matrix composite. A preform is subjected to one or more infiltrations with slurry comprised of a solvent, matrix binder, and particles. Removal of the solvent between infiltrations is achieved by making use of differing chemical or physical properties between the solvent and binder,