Rock Drill Insert With HCP Binder for Fracture Resistance
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Solution Overview
Problem
Previously known PCD inserts used in drilling are prone to brittle fracture, which significantly limits the service life of drilling bits and results in costly and time-consuming replacements, especially in long-hole drilling or hazardous environments.
Innovation Solution
A rock drill insert is designed with a substrate of cemented carbide comprising at least 5 wt.-% of a metallic binder, where the binder undergoes a phase transformation from face-centered cubic (FCC) to hexagonal close-packed (HCP) crystallographic form, particularly at a distance of 50 μm from the surface of the base portion, enhancing the toughness and reducing the risk of brittle failure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a PCD structure is bonded to a cemented carbide substrate with conventional binder content (8-12 vol.% Co), then wear resistance is improved, but brittle fracture resistance deteriorates
Solution Approach 1:
The invention changes the crystallographic phase parameter of the metallic binder from conventional FCC to HCP structure. This phase transformation fundamentally alters the material properties, enabling the binder to provide both wear resistance and improved brittle fracture resistance. The HCP phase exhibits different mechanical behavior compared to FCC, offering enhanced toughness while maintaining the protective function against wear.
Solution Approach 2:
The invention creates a composite structure where the HCP-phase metallic binder acts as a distinct phase within the cemented carbide matrix. This composite approach, with the binder comprising 15-30 vol.% of the substrate, allows the system to combine the hardness and wear resistance of the carbide particles with the toughness and ductility of the HCP-phase binder, resolving the contradiction between wear resistance and brittle fracture resistance.
2Reliability
If the binder content in cemented carbide is increased to improve toughness, then brittle fracture resistance is improved, but hardness and wear resistance deteriorate
Solution Approach 1:
The invention changes the crystallographic phase parameter of the metallic binder from conventional FCC to HCP structure. This phase transformation fundamentally alters the material properties, enabling the binder to provide both wear resistance and improved brittle fracture resistance. The HCP phase exhibits different mechanical behavior compared to FCC, offering enhanced toughness while maintaining the protective function against wear.
Solution Approach 2:
The invention creates a composite structure where the HCP-phase metallic binder acts as a distinct phase within the cemented carbide matrix. This composite approach, with the binder comprising 15-30 vol.% of the substrate, allows the system to combine the hardness and wear resistance of the carbide particles with the toughness and ductility of the HCP-phase binder, resolving the contradiction between wear resistance and brittle fracture resistance.
3Strength
If a PCD layer is applied to the tip surface to enhance wear resistance, then service life is improved, but the insert becomes more susceptible to brittle failure
Solution Approach 1:
The invention changes the crystallographic phase parameter of the metallic binder from conventional FCC to HCP structure. This phase transformation fundamentally alters the material properties, enabling the binder to provide both wear resistance and improved brittle fracture resistance. The HCP phase exhibits different mechanical behavior compared to FCC, offering enhanced toughness while maintaining the protective function against wear.
Solution Approach 2:
The invention creates a composite structure where the HCP-phase metallic binder acts as a distinct phase within the cemented carbide matrix. This composite approach, with the binder comprising 15-30 vol.% of the substrate, allows the system to combine the hardness and wear resistance of the carbide particles with the toughness and ductility of the HCP-phase binder, resolving the contradiction between wear resistance and brittle fracture resistance.
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 improved toughness of the rock drill insert significantly reduces the risk of brittle failure, leading to a longer service life of both the insert and the drill bit, thereby minimizing downtime and costs associated with frequent replacements.
Implementation Method 1
the binder undergoes a phase transformation from face-centered cubic (FCC) to hexagonal close-packed (HCP) crystallographic form
Data Source
AI summary
A rock drill insert a substrate having a tip portion and a base portion, wherein the tip portion includes a polycrystalline diamond (PCD) structure bonded to the substrate. The substrate is formed of a cemented carbide comprising at least 5 wt.-% of a metallic binder. At a distance of 50 μm from a surface of the base portion of the substrate, at least 20 vol.-% of the metallic binder is present in a hexagonal close packed (HCP) crystallographic form. Furthermore, a drill bit including a plurality of the above-described rock drill insert is disclosed, as well as a method for manufacturing the rock drill insert.