Polycrystalline Diamond Reaction Zone Carbon Diffusion Control

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Solution Overview

Problem

Conventional polycrystalline diamond constructions face weakness and embrittlement issues due to unwanted carbon diffusion from the diamond body into the substrate during high pressure/high temperature processing, leading to reduced service life.

Innovation Solution

A metallic substrate with a layer of carbide-forming powder material is used, which reacts with carbon to form a reaction zone that minimizes carbon back-diffusion into the substrate, while allowing solvent metal catalyst diffusion for sintering, thereby strengthening the interface attachment and improving service life.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If conventional HPHT processing is used to form polycrystalline diamond, then diamond grains can be bonded together to create a PCD structure, but carbon diffuses from the diamond body into the substrate causing weakness and embrittlement

Engineering Contradiction:

Improvebond strength between diamond body and substrateVSAvoidstructural integrity of PCD body

Core Design Contradiction:

StrengthVSReliability

Solution Approach 1:

A reaction zone comprising carbide-forming material is introduced as an intermediary layer between the substrate and diamond body. This reaction zone captures carbon diffusing from the diamond body through carbide formation, preventing carbon back-diffusion into the substrate that would cause embrittlement, while still allowing solvent catalyst diffusion for bonding.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The harmful carbon diffusion that causes embrittlement is converted into a beneficial reaction zone. The diffusing carbon reacts with carbide-forming material to create a controlled reaction zone that protects the substrate from carbon contamination while maintaining the bonding process.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

2Ease of manufacture

If solvent catalyst material is allowed to diffuse for sintering, then diamond grains can be bonded together, but carbon back-diffusion into substrate weakens the structure

Engineering Contradiction:

Improvesintering processVSAvoidstructural strength near interface

Core Design Contradiction:

Ease of manufactureVSStrength

Solution Approach 1:

The interface region is segmented into distinct zones: a reaction zone containing carbide-forming material positioned between the substrate and diamond body. This segmentation allows the reaction zone to selectively capture carbon while permitting solvent catalyst diffusion, thus enabling sintering without substrate embrittlement.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The reaction zone acts as an intermediary that selectively interacts with diffusing species - it captures carbon through carbide formation while allowing solvent metal catalyst to pass through and facilitate sintering of diamond grains.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Stability of the object's composition

If reaction zone is formed during HPHT processing, then carbon diffusion can occur, but the reaction zone weakens or embrittles the PCD body structure

Engineering Contradiction:

Improvecarbon diffusion controlVSAvoidstructural strength of PCD body

Core Design Contradiction:

Stability of the object's compositionVSStrength

Solution Approach 1:

The composition and structure of the reaction zone are controlled by selecting specific carbide-forming materials and adjusting their thickness and distribution. This parameter control allows the reaction zone to capture carbon effectively while maintaining adequate bond strength and preventing embrittlement.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The interface structure is designed as a composite system comprising substrate, reaction zone with carbide-forming material, and diamond body. This composite structure allows each layer to perform its specific function - the reaction zone captures carbon while maintaining structural integrity through controlled carbide formation.

Inventive Principle:

Principle #40Composite materials

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 engineered reaction zone enhances the bond strength between the diamond body and substrate, reducing embrittlement and improving the effective service life of the polycrystalline diamond constructions by controlling metallurgical properties near the interface.

Implementation Method 1

carbon that diffuses from the diamond powder

Methodology Applied

Scientific EffectDiffusion: Diffusion

Implementation Method 2

capable of carburizing or reacting with carbon

Methodology Applied

Scientific EffectCarburizing: Carburizing

Implementation Method 3

the solvent catalyst material within the substrate melts and infiltrates

Methodology Applied

Scientific EffectMelting: Melting

Implementation Method 4

infiltrates into the adjacent diamond grain volume

Methodology Applied

Scientific EffectInfiltration: Permeation

Implementation Method 5

subjected to high pressure/high temperature processing for sintering the diamond body and attaching the diamond body to the substrate

Methodology Applied

Scientific EffectSintering: Sintering

Data Source

PatentUS10933511B2Polycrystalline diamond constructions with modified reaction zone

Publication Date: 2021.03.02 SCHLUMBERGER TECH CORP

AI summary

Polycrystalline diamond constructions comprise a diamond body attached with a substrate during high pressure/high temperature processing, and include a modified reaction zone interposed between the body and substrate that is engineered to minimize or eliminate unwanted back diffusion of carbon from the diamond body into the substrate during the high pressure/high temperature processing.