Additive Manufacturing of Boron Carbide-Aluminum Composites for Neutron Collimators
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Solution Overview
Problem
Current methods are unable to produce boron carbide (B4C) - aluminum (Al) composites with complex geometries and high boron carbide content suitable for neutron collimators, as they typically result in lower than desirable boron carbide content and insufficient density.
Innovation Solution
A method for additive manufacturing of B4C-Al composites involving the production of a porous B4C preform by bonding boron carbide particles and infiltrating molten aluminum at 1000-1400°C to create a composite with 30-70 wt.% boron carbide content, enabling the formation of complex geometries and reducing hydrogen presence, which is a strong neutron scatterer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If conventional methods are used to produce B4C-Al composites, then the composites can be manufactured, but the boron carbide content is lower than desirable (less than 25 wt.%) and the density is insufficient
Solution Approach 1:
A porous B4C preform is produced first through additive manufacturing before aluminum infiltration. This preliminary structure allows precise control of B4C particle distribution and geometry, enabling high B4C content (30-70 wt.%) while maintaining density through the subsequent infiltration process that fills pores with aluminum metal
Solution Approach 2:
The invention changes the processing parameters by using additive manufacturing to create a porous preform with controlled porosity, then infiltrating at specific temperatures (1000-1400°C) to achieve the desired composite density and B4C content simultaneously
2Shape
If conventional methods are used to produce B4C-Al composites, then the composites can be manufactured, but they cannot be shaped into complex geometries suitable for collimator devices
Solution Approach 1:
The porous B4C preform with complex geometry is manufactured first using additive manufacturing technology, which excels at creating intricate shapes. This preliminary structuring enables complex collimator geometries that would be difficult or impossible to achieve with conventional casting or forging methods
Solution Approach 2:
Additive manufacturing allows different regions of the preform to have locally optimized properties, such as varying pore sizes and B4C particle distributions, which are then uniformly infiltrated with aluminum to maintain the complex geometry while achieving consistent composite properties throughout
3Object-generated harmful factors
If hydrogen is present in the composite, then the composite can be manufactured, but hydrogen acts as a strong incoherent scatterer that increases neutron radiation background
Solution Approach 1:
The invention extracts or removes hydrogen from the composite system by using aluminum metal infiltration instead of organic binders or resins that would contain hydrogen. The aluminum infiltration process creates a hydrogen-free composite structure, eliminating the source of incoherent neutron scattering while preserving the neutron absorption capabilities of B4C
Solution Approach 2:
By eliminating hydrogen, the invention converts a harmful element (hydrogen scatterer) into a benefit (hydrogen-free composite with reduced neutron background). The aluminum matrix provides structural support without introducing neutron scattering, thereby enhancing the overall neutron absorption performance of the B4C-Al composite
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
The method produces B4C-Al composites with higher boron content and complex geometries suitable for collimator devices, achieving high density and reduced neutron radiation background, while maintaining structural integrity and improved neutron absorption properties.
Implementation Method 1
infiltrating molten aluminum, at a temperature of 1000-1400° C., into pores of the porous preform
Implementation Method 2
Because boron carbide (B4C) has favorable neutron absorbing properties, it is desirable as a collimator material
Data Source
AI summary
A method for additive manufacturing of a composite object containing a bonded network of boron carbide particles and aluminum occupying spaces between boron carbide particles, the method comprising: (i) producing a porous preform constructed of boron carbide by an additive manufacturing process in which particles of boron carbide are bonded together; and (ii) infiltrating molten aluminum, at a temperature of 1000-1400° C., into pores of said porous preform to produce said composite object constructed of boron carbide particles within an aluminum matrix, wherein the boron carbide is present in the composite object in an amount of 30-70 wt. %. The resulting composite material is also herein described.