PCD Compact Elements Low-Temperature Braze Alloy Bonding
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Solution Overview
Problem
Polycrystalline diamond (PCD) composite compact elements face challenges in achieving superior mechanical properties, particularly thermal stability and secure attachment to substrates, due to residual solvent/catalyst material and limitations in bonding methods, which affect their performance in high-temperature applications like rock drilling.
Innovation Solution
A PCD composite compact element is developed with a thermally stable PCD structure bonded to a substrate using a braze alloy with specific melting onset temperatures and compositions, such as Ti, V, Cr, Mn, Zr, Nb, Mo, Hf, Ta, W, and Re elements, and a braze layer that infiltrates into the PCD structure, enhancing mechanical properties and attachment strength.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If conventional brazing methods are used to attach PCD to substrate, then attachment strength is improved, but thermal stability deteriorates due to heat damage to PCD
Solution Approach 1:
The patent changes the bonding parameters by using bond materials with melting onset temperatures below 1000°C (specifically 800-950°C), which are lower than conventional brazing temperatures. This parameter change allows bonding to occur at reduced temperatures that do not damage the PCD structure, thereby maintaining thermal stability while achieving adequate attachment strength.
Solution Approach 2:
The patent introduces a bond material as an intermediary substance between the PCD structure and substrate. This bond material serves as a mediator that enables bonding at lower temperatures, protecting the PCD from direct exposure to high temperatures while still providing secure attachment to the substrate.
2Temperature
If PCD structure is made thermally stable by removing solvent/catalyst material, then thermal stability is improved, but bonding capability deteriorates making attachment difficult
Solution Approach 1:
The patent changes the bonding approach by using bond materials with specific low melting onset temperatures (800-950°C) that are suitable for bonding thermally stable PCD. This parameter change in bond material selection enables bonding capability to be restored while maintaining the thermal stability of the PCD structure.
Solution Approach 2:
The patent uses a specially formulated bond material as an intermediary that can bond to both the thermally stable PCD structure and the substrate. This intermediary bond material compensates for the loss of bonding capability in thermally stable PCD by providing a bonding interface that works at lower temperatures.
3Strength
If high temperature brazing is used to ensure complete wetting and continuous reaction product layer, then attachment strength is improved, but PCD structural integrity deteriorates
Solution Approach 1:
The patent changes the temperature parameter for brazing to below 1000°C (specifically 800-950°C), which prevents the PCD from experiencing thermal damage while still achieving adequate wetting and bonding. This parameter change ensures both attachment strength and PCD structural integrity are maintained.
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 provides PCD composite compact elements with improved Young's modulus, transverse rupture strength, and thermal stability, enabling effective use in high-temperature applications like rock drilling with enhanced bonding strength and durability.
Implementation Method 1
a braze alloy with specific melting onset temperatures and compositions
Implementation Method 2
a braze layer that infiltrates into the PCD structure
Implementation Method 3
PCD may be made by subjecting an aggregated mass of diamond grains to an ultra-high pressure and temperature
Implementation Method 4
A material wholly or partly filling the interstices may be referred to as filler material. PCD may be formed in the presence of a sintering aid such as cobalt, which is capable of promoting the inter-growth of diamond grains. The sintering aid may be referred to as a solvent/catalyst material for diamond, owing to its function of dissolving diamond to some extent and catalyst its re-precipitation.
Data Source
AI summary
A polycrystalline diamond (PCD) composite compact element 100 comprising a substrate 130, a PCD structure 120 bonded to the substrate 130, and a bond material in the form of a bond layer 140 bonding the PCD structure 120 to the substrate 130; the PCD structure 120 being thermally stable and having a mean Young's modulus of at least about 800 GPa, the PCD structure 120 having an interstitial mean free path of at least about 0.05 microns and at most about 1.5 microns; the standard deviation of the mean free path being at least about 0.05 microns and at most about 1.5 microns. Embodiments of the PCD composite compact element may be for a tool for cutting, milling, grinding, drilling, earth boring, rock drilling or other abrasive applications, such as the cutting and machining of metal.