Earth-Boring Drill Bit Bodies Powder Metallurgy
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Solution Overview
Problem
Conventional earth-boring rotary drill bits face challenges in performance and durability as well bore depths increase, requiring multiple drill bits and incurring high costs due to equipment and time losses during bit changes, and existing particle-matrix composite materials are difficult to machine and require destructive mold removal.
Innovation Solution
The method involves forming bit bodies using powder compaction and sintering techniques, where a powder mixture of hard particles and matrix material is pressed with isostatic pressure to create a green body, which is then partially sintered and machined to form a bit body without a steel blank, allowing for increased durability and reduced shrinkage and distortion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If conventional infiltration process with graphite molds is used to form bit bodies, then bit bodies can be formed with particle-matrix composite material, but the process requires destructive mold removal and is difficult to machine
Solution Approach 1:
The patent changes the manufacturing parameters by transitioning from an infiltration process to a powder metallurgy process with controlled sintering. By adjusting sintering temperature, pressure, and atmosphere parameters, the bit body achieves both ease of manufacture and high dimensional accuracy without requiring destructive mold removal
Solution Approach 2:
The patent replaces the mechanical infiltration process with a thermal-field-based sintering process. Instead of forcing material into molds mechanically, the process uses controlled heating to sinter powder particles together, eliminating the need for destructive mold removal and improving dimensional accuracy
2Ease of manufacture
If bit bodies are formed using conventional methods with steel blanks, then manufacturing is feasible, but shrinkage and distortion occur during processing
Solution Approach 1:
The patent applies preliminary action by pre-forming the bit body geometry in the green state (after pressing but before sintering) and accounting for expected shrinkage during sintering.补偿 features are built into the green body design to compensate for thermal contraction, ensuring final dimensional accuracy
Solution Approach 2:
The patent controls shrinkage and distortion by optimizing sintering parameters including temperature gradient, holding time, and atmospheric composition. These parameter changes enable the material to densify uniformly without excessive distortion
3Length of moving object
If drill bits are used for increased well bore depths, then drilling capability is improved, but durability decreases requiring multiple bit changes
Solution Approach 1:
The patent uses composite materials consisting of hard particles (such as tungsten carbide, diamond, or cubic boron nitride) embedded in a metal matrix (such as cobalt, nickel, or copper-based alloys). This composite structure provides both the hardness needed for deep well drilling and the toughness required for extended durability
Solution Approach 2:
The patent optimizes the particle size distribution, volume fraction, and spatial arrangement of hard particles within the matrix to enhance both drilling depth capability and bit durability. The controlled distribution ensures uniform wear resistance throughout the bit body
4Strength
If particle-matrix composite materials are used for bit bodies, then cutting performance is improved, but the materials are difficult to machine
Solution Approach 1:
The patent performs preliminary shaping of the bit body during the green state (after pressing, before sintering) when the material is still relatively soft and easy to machine. Complex geometries, internal passages, and mounting features are formed by machining or molding the green body, avoiding the need to machine the hard sintered material
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
This approach enhances the durability and dimensional accuracy of bit bodies, reducing the need for multiple drill bits and minimizing equipment and time costs by forming bit bodies with improved particle distribution and density, enabling more efficient drilling operations.
Implementation Method 1
pressed with isostatic pressure to create a green body
Implementation Method 2
which is then partially sintered and machined to form a bit body
Data Source
AI summary
Methods for forming bodies of earth-boring drill bits and other tools include milling a plurality of hard particles and a plurality of particles comprising a matrix material to form a mill product comprising powder particles, separating the particles into a plurality of particle size fractions. Some of the particles from the fractions may be combined to form a powder mixture, which may be pressed to form a green body. Additional methods include mixing a plurality of hard particles and a plurality of particles comprising a matrix material to form a powder mixture, and pressing the powder mixture with pressure having an oscillating magnitude to form a green body. In yet additional methods a powder mixture may be pressed within a deformable container to form a green body and drainage of liquid from the container is enabled as the powder mixture is pressed.