Simulation of Retention of a Diamond Particle in a Matrix of Diamond-Impregnated Tools
At a Glance
Section titled âAt a Glanceâ| Metadata | Details |
|---|---|
| Publication Date | 2016-01-01 |
| Journal | Journal of the Japan Society of Powder and Powder Metallurgy |
| Authors | J. Borowiecka-JamroĆŒek, J. Lachowski |
| Institutions | Kielce University of Technology |
| Citations | 2 |
| Analysis | Full AI Review Included |
Technical Documentation & Analysis: Diamond Retention in Powder Metallurgy Matrices
Section titled âTechnical Documentation & Analysis: Diamond Retention in Powder Metallurgy MatricesâThis documentation analyzes the findings of âSimulation of Retention of a Diamond Particle in a Matrix of Diamond-Impregnated Toolsâ and connects the material requirements to the advanced capabilities of 6CCVDâs MPCVD diamond products.
Executive Summary
Section titled âExecutive SummaryâThe research provides critical insights into optimizing diamond retention in metal-matrix composite tools, a core challenge in powder metallurgy applications like circular saw segments.
- Core Value Proposition: Diamond retention in metallic matrices (Co, Co-Fe, Co-W) is achieved through mechanical bonding resulting from matrix shrinkage during the cooling phase of hot pressing.
- Critical Mechanism: Retention strength is primarily governed by the stress and strain fields generated due to the significant thermal expansion coefficient (CTE) mismatch between the metal matrix and the diamond particle.
- Key Metric: The total strain energy (elastic plus plastic deformation energy) accumulated in the matrix surrounding the diamond particle is confirmed as a reliable quantitative estimator of the matrixâs retentive properties.
- Process Dependence: The magnitude of the stress/strain fields and the resulting retention force are strongly dependent on the diamond particleâs protrusion height (0 to 150 ”m) above the matrix surface.
- Material Performance: While all matrices showed similar plastic-to-total energy ratios (approx. 60%), the specific composition (e.g., Co(SMS) vs. Co(EF)W) significantly influenced the total strain energy and the force required for particle pullout.
- Methodology: The analysis utilized Finite Element Method (FEM) simulations (ABAQUS) to model thermal shrinkage and external load application (up to 50 N) on a 350 ”m truncated octahedral diamond particle.
Technical Specifications
Section titled âTechnical SpecificationsâThe following hard data points were extracted from the analysis of the hot pressing process and material properties.
| Parameter | Value | Unit | Context |
|---|---|---|---|
| Hot Pressing Temperature Range | 850 - 980 | °C | Range used for various matrix compositions |
| Hot Pressing Pressure Range | 35 - 40 | MPa | Applied during sintering process |
| Hot Pressing Duration | 2 | min | Time held at peak parameters |
| Diamond Particle Size (Modeled) | 350 | ”m | Distance between opposite square walls (truncated octahedron) |
| Diamond Concentration (Simulated) | 15 | Relative Measure | Equivalent to 25% volume (4.4 carats / 1 cm3) |
| Protrusion Range Analyzed | -0.6 to 0.2 | mm | Negative protrusion (submerged) to 200 ”m protrusion |
| Maximum External Load Applied | 50 | N | Normal force applied during simulated pullout |
| Co(SMS) Ultimate Tensile Strength (Rm) | 865 | MPa | Highest Rm reported among pure Co matrices |
| Co(EF) Yield Strength (R0.2) | 634 | MPa | Highest R0.2 reported among pure Co matrices |
| Diamond CTE (at 300 K) | 1 x 10-6 | K-1 | Coefficient of Thermal Expansion (CTE) |
| Cobalt CTE (at 300 K) | 13.4 x 10-6 | K-1 | Significant mismatch driving retention stress |
| Plastic Strain Energy Share | ~60 | % | Percentage of total strain energy across all matrices |
Key Methodologies
Section titled âKey MethodologiesâThe experimental and simulation procedures focused on creating and analyzing metal-diamond composite segments via powder metallurgy.
- Powder Preparation: Elemental powders (Cobalt SMS, Extrafine Cobalt, 400 mesh Cobalt, Carbonyl Iron, Tungsten WP30) were mixed with natural or synthetic diamond powder.
- Hot Pressing: Specimens were produced in an inert nitrogen atmosphere under controlled conditions: 35-40 MPa pressure, 2 min duration, and temperatures ranging from 850 °C to 980 °C, depending on the matrix composition.
- Mechanical Characterization: Static tensile tests were performed on the sintered matrix materials to determine key mechanical properties (Rm, R0.2, ÎL/L).
- Thermal Shrinkage Simulation: The cooling phase following hot pressing was modeled using the Finite Element Method (FEM) via ABAQUS (ver. 6.14). This simulated the thermal shrinkage of the matrix and the resulting stress/strain fields around the diamond particle.
- Retention Analysis: The simulation analyzed a 350 ”m truncated octahedral diamond particle, varying its protrusion height from fully submerged (negative protrusion) to 150 ”m protruding above the matrix surface.
- External Load Simulation: A pullout simulation was conducted by applying a maximum external force of 50 N (normal and tangential) to the diamond particle to quantify the force required for removal and correlate it with the calculated strain energy.
6CCVD Solutions & Capabilities
Section titled â6CCVD Solutions & CapabilitiesâThis research confirms that the performance of diamond-impregnated tools is fundamentally limited by the quality and thermal stability of the diamond material and the interface bonding. 6CCVD provides the high-specification MPCVD diamond materials necessary to replicate and advance this critical research.
Applicable Materials
Section titled âApplicable MaterialsâTo ensure optimal thermal mismatch and mechanical integrity in high-performance matrix tools, 6CCVD recommends the following materials:
- Polycrystalline Diamond (PCD) Plates: Ideal source material for crushing into high-quality grits (350 ”m range) used in powder metallurgy. Our MPCVD PCD offers superior thermal stability and toughness compared to traditional synthetic grits, ensuring the particle withstands the high temperatures (up to 980 °C) and pressures (40 MPa) of the hot pressing process without degradation.
- Capability Match: We offer PCD plates up to 125mm in diameter and thicknesses up to 500 ”m, providing scalable source material for industrial segment production.
- Optical Grade Single Crystal Diamond (SCD): For research requiring the most precise and consistent thermal properties, our SCD material provides the lowest and most uniform Coefficient of Thermal Expansion (CTE) (1 x 10-6 K-1). This maximizes the thermal mismatch effect, which the paper identifies as the primary driver for mechanical retention.
- Capability Match: SCD plates available from 0.1 ”m to 500 ”m thick, with polishing quality better than Ra < 1nm.
Customization Potential
Section titled âCustomization PotentialâThe paper highlights the complex interaction between the diamond and the metal matrix (Co, Fe, W). 6CCVD offers specialized services to optimize this interface:
| Research Requirement | 6CCVD Customization Service |
|---|---|
| Interface Optimization | Custom Metalization: We offer in-house deposition of thin films (Au, Pt, Pd, Ti, W, Cu) on both SCD and PCD surfaces. Pre-coating the diamond grits with a refractory metal like Ti or W can enhance chemical bonding and wettability with the Co/Fe matrix, potentially improving retention beyond the purely mechanical effects studied. |
| Specific Dimensions/Shapes | Precision Laser Cutting: While the paper modeled a 350 ”m truncated octahedron, 6CCVD can provide custom laser cutting and shaping services for SCD and PCD substrates, allowing researchers to test non-standard geometries or large-area segments (up to 125mm). |
| High-Quality Surface Finish | Advanced Polishing: Our capability to polish inch-size PCD to Ra < 5nm ensures that the starting material for grits is defect-free, minimizing stress concentration points that could lead to premature failure during the hot pressing cycle. |
Engineering Support
Section titled âEngineering Supportâ6CCVDâs in-house PhD material science team specializes in the thermal, mechanical, and electronic properties of MPCVD diamond. We offer comprehensive support for engineers and scientists working on advanced tooling and composite projects.
- We provide consultation on selecting the optimal diamond material (SCD vs. PCD) and grade (e.g., thermal vs. electronic) to meet specific requirements for diamond-impregnated tool applications.
- Our team can assist in analyzing the impact of CTE mismatch and thermal stability on retention properties, helping clients design matrices that maximize the beneficial strain energy identified in this research.
For custom specifications or material consultation, visit 6ccvd.com or contact our engineering team directly. We offer global shipping (DDU default, DDP available) to ensure timely delivery of your critical materials.
View Original Abstract
The main objectives of the paper are numeric calculations of retention of diamond particle in metallic-diamond segments of circular saws. The segments are produced by means of the technology of powder metallurgy. The analysis has been preformed for cobalt, cobalt-iron and cobalt-tungsten sinters. The effective use of diamond impregnated tools is strongly depended on the retentive properties of the metal matrix, which must hold diamond grits firmly. Due to mismatch between thermal expansion coefficients of the matrix and diamond, the mechanical fields are generated in the matrix at diamond surroundings. The fields play a major role for retentive properties of matrix. It has been postulated that the potential retentive capability of a matrix can be associated with the amount of elastic and plastic deformation energy which occurs in the matrix around diamond particles.