Polycrystalline Diamond Cutting Elements With Laser Catalyst Removal
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Solution Overview
Problem
Polycrystalline diamond compact cutting elements in earth-boring tools face thermal damage and deterioration due to catalyst material remaining in interstitial spaces between diamond grains, leading to thermal expansion issues and chemical breakdown at high temperatures.
Innovation Solution
A method using electromagnetic radiation, specifically a focused energy beam with a wavelength between 200 nm and 800 nm, to ablate the interstitial catalyst material without degrading the diamond grains or their bonds, thereby removing the catalyst from the polycrystalline diamond compact.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If catalyst material is used during HTHP sintering to bond diamond grains, then the diamond table can be formed with inter-granular bonds, but catalyst material remains in interstitial spaces causing thermal damage and chemical breakdown at high temperatures
Solution Approach 1:
The patent extracts the harmful catalyst material from the interstitial spaces between diamond grains using a laser beam. The laser selectively removes the catalyst material while leaving the diamond grains and their inter-granular bonds intact, thereby eliminating the source of thermal damage and chemical breakdown.
Solution Approach 2:
The patent changes the physical state of the catalyst material by using laser energy to heat and vaporize it from the interstitial spaces. This parameter change (from solid to vapor phase) allows selective removal of the catalyst without affecting the diamond structure.
2Ease of manufacture
If catalyst material remains in the diamond table, then the HTHP sintering process is simplified, but internal stress develops at temperatures exceeding 350°C due to differential thermal expansion between diamond and catalyst
Solution Approach 1:
The laser beam extracts the catalyst material from the diamond table, eliminating the source of differential thermal expansion. This removes the cause of internal stress development while preserving the diamond grains and their bonds.
Solution Approach 2:
The patent changes the composition parameter of the diamond table by selectively removing the catalyst material. This parameter change eliminates the thermal expansion mismatch between diamond and catalyst, thereby improving thermal stability.
3Ease of manufacture
If catalyst material is present in the diamond table, then the sintering process is straightforward, but at temperatures of 750°C and above, stresses increase significantly causing cracks to form and propagate within the diamond table
Solution Approach 1:
The laser beam removes the catalyst material from the diamond table, eliminating the source of thermal stresses that cause crack formation and propagation at high temperatures. This extraction improves crack resistance while maintaining the diamond structure.
Solution Approach 2:
The patent changes the compositional parameter by removing the catalyst material, which eliminates the thermal expansion coefficient mismatch. This parameter change prevents the development of high stresses that would otherwise cause cracking at elevated temperatures.
4Ease of manufacture
If catalyst material remains in interstitial spaces, then the diamond table formation is simplified, but diamond crystals undergo chemical breakdown or back-conversion to graphite at high temperatures
Solution Approach 1:
The laser beam extracts the catalyst material from the interstitial spaces, removing the agent that causes chemical breakdown and back-conversion of diamond to graphite. This extraction preserves the chemical stability of the diamond crystals.
Solution Approach 2:
The patent changes the chemical composition parameter by selectively removing the catalyst material. This parameter change eliminates the chemical interaction between catalyst and diamond that would otherwise cause decomposition or phase transformation at high temperatures.
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 effectively removes interstitial material from the cutting elements, reducing thermal stress and chemical breakdown, enhancing the thermal stability and durability of the cutting elements.
Implementation Method 1
A method using electromagnetic radiation, specifically a focused energy beam with a wavelength between 200 nm and 800 nm, to ablate the interstitial catalyst material without degrading the diamond grains or their bonds
Implementation Method 2
ablating the interstitial material with the at least one energy beam such that at least a portion of the interstitial material is removed from a first region of the volume of polycrystalline superabrasive material
Data Source
AI summary
A method of forming a cutting element for an earth-boring tool may include directing at least one energy beam at a surface of a volume of polycrystalline superabrasive material including interstitial material disposed in regions between inter-bonded grains of polycrystalline superabrasive material. The method includes ablating the interstitial material with the at least one energy beam such that at least a portion of the interstitial material is removed from a first region of the volume of polycrystalline superabrasive material without any substantial degradation of the inter-bonded grains of superabrasive material or of bonds thereof in the first region.