Porous Mold Injection for Ceramic Composite Parts
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for producing oxide/oxide or ceramic matrix composite materials are limited in thickness and mechanical properties, particularly in resistance to delamination and shear stresses, and struggle with controlling pressure gradients during the infusion of a loaded slip into thick or complex geometries, leading to porosity issues.
Innovation Solution
A method involving a porous material mold within a rigid enclosure allows for controlled injection and drainage of a slip containing refractory ceramic particles, ensuring homogeneous sedimentation and high matrix volume ratio, using a porous medium to facilitate pressure transfer and liquid evacuation without disturbing the particles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If pressure gradient processes (infusion, RTM, APS) are used to penetrate loaded slip into thick fibrous textures, then the thickness of the part can reach several tens of millimeters, but the pressure difference between areas near vents and areas further away creates porosity and disturbs particle distribution
Solution Approach 1:
The invention divides the mold into two distinct functional parts: a porous mold body that provides uniform capillary action throughout the fibrous texture, and a separate rigid enclosure that provides structural support and contains evacuation vents. This segmentation allows the porous portion to handle slip penetration uniformly while the rigid portion manages liquid evacuation, resolving the pressure gradient issue that causes porosity and particle distribution problems in conventional single-piece molds.
2Ease of manufacture
If conventional molds are used for slip casting, then the process is simple, but the liquid phase evacuation disturbs the distribution of solid particles and creates significant porosities
Solution Approach 1:
The invention employs a porous mold body made of refractory ceramic material with controlled porosity that enables uniform capillary absorption of the liquid slip throughout the fibrous texture. This porous structure allows the liquid phase to be evacuated uniformly through capillary action without creating the pressure gradients that disturb particle distribution, thereby eliminating porosity formation while maintaining process simplicity.
3Strength
If the mold is made entirely of rigid material with evacuation vents, then structural strength is provided, but pressure gradient control is difficult and porosity occurs
Solution Approach 1:
The invention creates a composite mold structure combining two different materials with complementary properties: a porous refractory ceramic material that provides uniform capillary action for slip penetration, and a rigid material (metal or plastic) that provides structural strength and contains evacuation vents. This composite approach allows each material to perform its optimal function, resolving the contradiction between structural strength and pressure gradient control.
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 mechanical properties of the composite material by achieving a low macroporosity rate and improved resistance to delamination, while allowing for the production of thick or complex geometries with better control over particle distribution and pressure management.
Implementation Method 1
draining the liquid from the slip having passed through the fibrous texture
Implementation Method 2
injecting under pressure a slip containing a powder of refractory ceramic particles into the fibrous texture
Implementation Method 3
sintering of the ceramic particles refractories present in the fibrous preform in order to form a refractory matrix in said preform
Data Source
Figure 1
Figure 2~3
AI summary
A process for manufacturing a composite material part comprises the following steps: - pressurized injecting of a slurry (150) containing a powder of refractory ceramic particles (1500) into a fibrous structure, - draining the liquid (1501) of the slurry (150) that has passed through the fibrous structure (10) and retaining the powder of refractory ceramic particles inside said structure so as to obtain a fibrous preform (15) loaded with refractory ceramic particles (1500). The injection equipment comprises a mould made of porous material (110) comprising an internal housing (113) in which the fibrous structure is placed, the slurry (150) being injected into the fibrous structure (10) through at least one injection port (134) present on the injection equipment and opening into the internal housing (113) of the mould made of porous material (110). The equipment also comprises a chamber made of rigid material (130) in which the mould made of porous material (110) is held during the pressurized injection of the slurry (150) and the drainage of the liquid (1501) of said slurry, the liquid (1501) of the slurry being discharged through at least one vent (135) present on the chamber made of rigid material.