Polycrystalline Diamond Cutting Element Double Pressing Stress Relief
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
High-temperature, high-pressure sintering of PCD cutting elements often results in cracking due to stress development during the forming process, limiting their wear life.
Innovation Solution
A 'double pressing' process where previously HTHP pressed PCD material is leached of metallic materials, crushed, and then layered with diamond filler for a second HTHP sintering cycle, or alternatively, using spark plasma sintering to form PCD cutting elements with optimized stress fields and improved wear resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If high-temperature, high-pressure sintering is used to form PCD cutting elements, then the cutting elements achieve superhard properties and wear resistance, but stress development during the forming process causes cracking that limits wear life
Solution Approach 1:
The patent applies preliminary action by performing a first HTHP pressing operation to create a green body with embedded stress relief structures (voids or inclusions) before the final sintering process. These pre-positioned stress relief features are designed to accommodate and distribute thermal and mechanical stresses during subsequent high-temperature processing, preventing crack formation and improving the overall reliability and wear life of the PCD cutting element while maintaining its superhard properties
2Productivity
If a single HTHP pressing operation is used to form PCD cutting elements, then the manufacturing process is simple and fast, but the resulting product has cracking and reduced wear life
Solution Approach 1:
The patent applies segmentation by dividing the manufacturing process into two distinct HTHP pressing operations. The first operation creates a green body with embedded stress relief structures, while the second operation completes the sintering process to achieve final density and hardness. This segmented approach allows the product to achieve both high reliability (reduced cracking) and maintains reasonable productivity by using efficient HTHP pressing operations for each stage
3Strength
If PCD material contains metallic binder-catalyzing material, then the diamond particles bond effectively during sintering, but the metallic residue limits the maximum useful operating temperature
Solution Approach 1:
The patent applies the taking out principle by selectively removing or minimizing metallic binder-catalyzing materials from the PCD cutting element structure. By extracting these metallic components that limit high-temperature performance, the patent enables the PCD material to operate at higher temperatures while maintaining effective diamond-to-diamond bonding through alternative mechanisms or reduced metallic content formulations
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 double pressing method enhances wear life by up to tenfold, with improved abrasion resistance and stress relief in the final product, while spark plasma sintering allows for rapid production of high-quality PCD cutting elements with enhanced performance.
Implementation Method 1
PCD cutting elements may be formed by sintering diamond powder with a suitable binder-catalyzing material with a substrate of less hard material in a high-pressure, high-temperature press
Implementation Method 2
a previously HTHP pressed PCD material that has been leached or rendered free of all or substantially all of the metallic material
Implementation Method 3
spark plasma sintering to form PCD cutting elements with optimized stress fields and improved wear resistance
Data Source
AI summary
A polycrystalline-diamond cutting element for a drill bit of a downhole tool. The cutting element includes a substrate and a diamond table bonded to the substrate. The diamond table includes a diamond filler with at least one leached polycrystalline diamond segment packed therein along at least one working surface thereof. The cutting element may be formed by positioning the diamond table on the substrate and bonding the diamond table onto the substrate such that the polycrystalline diamond segment is positioned along at least one working surface of the diamond table. A spark plasma sintering or double press operation may be used to bond the diamond table onto the substrate.