Contoured PCD and PCBN Twist Drill Tips via HPHT Sintering
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The manufacturing of helical or fluted PCD and PCBN cutting tools is complex and costly due to the difficulty in shaping superhard materials under HPHT sintering, leading to high production costs and mechanical weaknesses, which limits their adoption in drilling and milling applications.
Innovation Solution
A method for producing near-to-net shape helical solid PCD and PCBN tips using a precursor mold with shaped openings, filled with specially prepared powder, and subjected to HPHT conditions, allowing for easier fabrication and attachment to conventional tool substrates, reducing manufacturing costs and improving tool performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Shape
If conventional shaping processes like grinding are used to create helical shapes in PCD or PCBN, then the cutting face can achieve the desired fluted or helical shape, but the manufacturing cost increases significantly and the process becomes very tedious
Solution Approach 1:
The invention applies preliminary action by incorporating the helical shape directly into the precursor mold before the HPHT sintering process. The precursor mold contains helical cavities that form the desired fluted shape during sintering, eliminating the need for subsequent grinding operations to create the helical geometry.
Solution Approach 2:
The invention replaces the mechanical grinding system with a chemical-thermal process. Instead of using mechanical abrasion to shape the PCD or PCBN after sintering, the helical shape is formed through the HPHT sintering process itself, where the precursor material transforms under heat and pressure to match the mold cavity geometry.
2Strength
If helical shapes are fabricated from PCD or PCBN under HPHT sintering process, then the superabrasive material characteristics are maintained, but the cell designs become complex and difficult to implement
Solution Approach 1:
The invention applies segmentation by separating the shaping function from the sintering process. The precursor mold contains pre-formed helical cavities that segment the sintering cell into specific geometric zones, allowing the HPHT process to directly produce the desired shape without requiring complex modifications to the sintering apparatus itself.
Solution Approach 2:
The invention introduces an intermediary element - the precursor mold - that mediates between the simple HPHT sintering process and the complex helical shape requirement. The mold acts as a template that translates the isotropic pressure and temperature fields into anisotropic shape formation, simplifying the overall cell design while achieving complex geometries.
3Reliability
If veined PCD drills are used to improve product life, then the tool performance is enhanced, but the fabrication joints become weak and the price becomes very expensive
Solution Approach 1:
The invention merges the PCD or PCBN material with the tool substrate by creating a monolithic structure through the HPHT sintering process. The precursor mold and substrate material are sintered together in one operation, eliminating separate fabrication joints and creating a unified structure where the superabrasive material and substrate are bonded at the molecular level during sintering.
Solution Approach 2:
The invention uses composite materials by combining the superabrasive precursor powder with substrate material in a controlled mixture before loading into the precursor mold. This creates a composite green body that, when sintered, produces a unified structure with optimized properties combining both the superhard phase and the substrate material.
4Ease of manufacture
If PCD inserts are made shallow to reduce cost, then the manufacturing cost decreases, but the tools cannot be resharpened and the mechanical strength is reduced
Solution Approach 1:
The invention applies universality by designing the precursor mold to produce full-depth helical structures that serve multiple functions: they provide the cutting edge geometry, ensure adequate insert depth for mechanical strength, and enable resharpening capability. The single sintering process produces an insert that can be used, resharpened, and reused multiple times.
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 method results in cost-effective, high-quality helical PCD and PCBN tools with improved durability and versatility, suitable for a broader range of applications, including aerospace and automotive industries, with reduced grinding time and increased flexibility in tool designs.
Implementation Method 1
subjected to a pressure, temperature and time conditions suitable for diamond synthesis or PCD/PCBN sintering
Data Source
AI summary
Contoured solid polycrystalline superabrasive material such as twist drill tips and endmill flank segments can be formed by preparing a precursor mold having a plurality of shaped openings each corresponding to a predetermined shape. A specially prepared charge feed can be placed into the shaped openings to form a charged precursor. The charge feed can include a substantially homogeneous mixture of superabrasive source particulates, sintering binder, and optional inorganic bonding medium. A loaded reaction cup-assembly including the charged precursor can be subjected to a pressure, temperature and time sufficient for sintering and formation of the contoured polycrystalline superabrasive material. Reduced finishing steps and increased tailorability of grade and quality of final polycrystalline products can be readily achieved.