Bimodal Tungsten Carbide Substrate for Earth-Boring Cutting Elements
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Solution Overview
Problem
Conventional cutting elements for earth-boring tools face issues with catalyst material eruptions and poor durability due to uneven pore distribution and pressure build-up during the high-pressure/high-temperature sintering process, leading to weakened diamond tables with macro-sized intrusions and reduced wear resistance.
Innovation Solution
A cutting element is formed using a supporting substrate with a mixture of coarse and fine tungsten carbide particles, providing a uniform distribution of pores and pore throats, allowing for uniform binder flow and preventing eruptions, resulting in a more robust and durable diamond table with improved wear resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a monomodal grain size distribution of carbide material is used in the cutting element substrate, then the substrate structure is simplified, but the pore distribution becomes uneven and requires increased pressure during sintering, resulting in catalyst material eruptions and poor durability
Solution Approach 1:
The patent changes the grain size distribution parameter from monomodal to bimodal, combining coarse carbide particles (4-10 μm) with fine carbide particles (0.5-2 μm). This parameter modification creates a more uniform pore distribution and reduces capillary pressure during sintering, preventing catalyst eruptions while maintaining substrate structural integrity and improving cutting element durability
Solution Approach 2:
The patent creates a composite carbide substrate structure by combining two different particle size ranges. The coarse particles provide structural framework while fine particles fill interstices to create uniform pore distribution. This composite approach balances structural requirements with sintering performance, eliminating catalyst eruptions without compromising substrate strength
2Power
If increased pressure is applied during HPHT sintering to force catalyst material through pore throats, then the sintering process can proceed, but the pore throats fracture and catalyst material erupts into the diamond grains, depleting the substrate and creating macro-sized intrusions that disrupt the diamond structure
Solution Approach 1:
The patent modifies the pore structure parameters by using bimodal carbide particle distribution, which increases the average pore throat size and creates a more uniform pore distribution. This structural modification reduces the capillary pressure required for catalyst flow during sintering, allowing the process to proceed at lower pressures without fracturing pore throats or causing catalyst eruptions that would compromise diamond table quality
Solution Approach 2:
The patent prepares the substrate structure in advance by creating a bimodal particle distribution that inherently provides better pore connectivity and larger pore throats. This pre-conditioning of the substrate structure cushions against the high pressures of HPHT sintering, preventing pore throat fracture and catalyst eruptions before they can occur during the sintering process
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 solution enhances the quality, reliability, and toughness of the cutting element by preventing binder eruptions and macro-sized intrusions, leading to improved wear resistance and durability.
Implementation Method 1
The at least substantially uniform distribution of pores and an at least substantially uniform distribution of pore throat sizes throughout the supporting substrate may provide an at least substantially uniform capillary pressure profile, which may facilitate uniform flow of the binder material through the supporting substrate
Implementation Method 2
sintering the supporting substrate and the diamond particles to form a cutting table comprising inter-bonded diamond particles attached to the supporting substrate
Data Source
AI summary
A method of forming a cutting element includes forming a supporting substrate comprising a homogenized binder and a mixture of coarse tungsten carbide (WC) particles and fine WC particles, depositing discrete diamond particles on the supporting substrate, and sintering the supporting substrate and the diamond particles to form a cutting table comprising inter-bonded diamond particles attached to the supporting substrate. A ratio of a particle size of the coarse WC particles to a particle size of the fine WC particles is within a range of from about 2:1 to about 50:1. The mixture of coarse WC particles and fine WC particles include between about 60% by volume (vol %) and 95 vol % coarse WC particles and between about 5 vol % and 40 vol % fine WC particles. Cutting elements so produced and earth-boring tools including such cutting elements are also disclosed.