Development of a Diamond Composite in the NI-CO-FE3P-SN-WC System Via Free Sintering for Use in Multi-Find Diamond Pearls
At a Glance
Section titled âAt a Glanceâ| Metadata | Details |
|---|---|
| Publication Date | 2024-11-08 |
| Journal | Revista de GestĂŁo Social e Ambiental |
| Authors | Mateus Valentim Simmer Sopeletto, Alexandre Vianna Bahiense, Victor Moza Ponciano, Carlos Eduardo Gomes Ribeiro, Gustavo de Castro Xavier |
| Analysis | Full AI Review Included |
Technical Documentation & Analysis: Diamond Composite for Multi-Find Diamond Pearls
Section titled âTechnical Documentation & Analysis: Diamond Composite for Multi-Find Diamond PearlsâExecutive Summary
Section titled âExecutive SummaryâThis research successfully developed and characterized a novel diamond composite matrix (NICOFE: Ni-Co-Fe<sub>3</sub>P-Sn-WC) via Powder Metallurgy and Free Sintering, aimed at reducing cobalt usage in diamond wire saw pearls.
- Cobalt Reduction Strategy: The NICOFE alloy partially substituted Cobalt (Co) with Nickel (Ni) to achieve environmental and economic advantages in the ornamental stone cutting industry.
- Performance Validation: The resulting NICOFE pearls demonstrated compressive strength (0.95 to 1.12 GPa) comparable to commercial reference samples (1.00 to 1.20 GPa), confirming the viability of the Ni-based substitution.
- Material Specification: The composite utilized Ti-coated, cubic octahedral synthetic diamond (HWD 92 Ti series) at a standard FEPA concentration of 0.35 g/cm<sup>3</sup>.
- Process Parameters: Sintering was conducted using a controlled reducing atmosphere (70% H<sub>2</sub> / 30% N<sub>2</sub>) with a peak temperature of 960°C.
- Critical Failure Mechanism: Microstructural analysis (MEV/EDS) revealed significant porosity and point defects in the diamond-matrix transition zone of the NICOFE composite, leading to insufficient adhesion and diamond âpull-out.â
- Future Direction: The study concludes that further optimization of elemental powder proportions and sintering parameters is required to eliminate transition zone defects and maximize final composite resistance.
Technical Specifications
Section titled âTechnical Specificationsâ| Parameter | Value | Unit | Context |
|---|---|---|---|
| Target Application | Diamond Wire Saw Pearls | N/A | Cutting ornamental stones (Multi-wire technology) |
| Matrix Composition (Ni) | 50 | % | Nickel content (Cobalt substitute) |
| Matrix Composition (Co) | 25 | % | Cobalt content |
| Matrix Composition (Fe<sub>3</sub>P) | 18 | % | Iron Phosphorus content |
| Matrix Composition (Sn) | 3.5 | % | Tin content |
| Matrix Composition (WC) | 3.5 | % | Tungsten Carbide content |
| Diamond Concentration (FEPA) | 0.35 | g/cm<sup>3</sup> | Standard concentration used |
| Diamond Type | HWD 92 Ti Series | N/A | Monocrystalline, Ti-coated, cubic octahedral |
| Sintering Peak Temperature (Zone III) | 960 | °C | Free Sintering process |
| Sintering Atmosphere | 70% H<sub>2</sub> / 30% N<sub>2</sub> | % | Reducing and nitriding environment |
| Conveyor Speed | 60 | mm/minute | Sintering furnace parameter |
| Theoretical Composite Density | 8.17 | g/cm<sup>3</sup> | Calculated density |
| Pearl External Diameter (ĂExt) | 7.3 | mm | Standard multiwire dimension |
| Pearl Internal Diameter (ĂInt) | 5.0 | mm | Standard multiwire dimension |
| NICOFE Compressive Strength (Elastic Zone) | 0.95 to 1.12 | GPa | Comparable to commercial samples |
| Commercial A Compressive Strength (Elastic Zone) | 1.00 to 1.20 | GPa | Reference material |
Key Methodologies
Section titled âKey MethodologiesâThe diamond composite pearls were manufactured using Powder Metallurgy techniques, focusing on precise control of elemental powders and sintering conditions.
- Material Selection and Preparation:
- Elemental powders (Ni, Co, Fe<sub>3</sub>P, Sn, WC) were sourced with particle sizes < 44 ”m and purities > 99.5%.
- Diamond grit (HWD 92 Ti series) was used, distributed across three particle sizes (35/40, 40/50, 50/60 mesh).
- Mixing and Granulation:
- Elemental powders and diamond grit were mixed for 180 minutes (Dr. Fritsch MP - 10 mixer) to ensure homogenization.
- Magnesium stearate (0.1% mass fraction) was added to facilitate compaction.
- Granulation (Dr. Fritsch GA 300) was performed to agglomerate fine particles (< 44 ”m) and prevent flow obstruction during pressing.
- Cold Uniaxial Compaction:
- Green pearls were shaped at room temperature using a Dr. Fritsch BPC 100 automatic hydraulic press.
- The process utilized a four-part matrix system (double compaction action) to achieve strict control of mass (1.18 g) and density (5.1 g/cm<sup>3</sup>).
- Free Sintering:
- Sintering was carried out in a continuous furnace (Bertoncello GBF 180) across three heating zones.
- The temperature profile was programmed sequentially: Zone I (480°C), Zone II (780°C), and Zone III (960°C).
- A controlled reducing atmosphere (70% H<sub>2</sub> / 30% N<sub>2</sub>) was maintained to prevent oxidation and promote surface nitriding.
- Characterization:
- Uniaxial compressive strength tests were performed (EMIC DL 100KN universal testing machine) at a speed of 1 mm/minute.
- Microstructural analysis, phase identification, and qualitative chemical composition were determined using Scanning Electron Microscopy (MEV) coupled with Dispersive Energy Spectroscopy (EDS) (HITACHI TN 3030 Plus).
6CCVD Solutions & Capabilities
Section titled â6CCVD Solutions & CapabilitiesâThe research highlights the critical challenge in diamond composite manufacturing: ensuring robust adhesion between the diamond crystal and the metallic matrix, especially when substituting traditional binders like Cobalt. 6CCVD, as an expert in MPCVD diamond materials and advanced processing, offers tailored solutions to overcome the transition zone defects (porosity, pull-out) observed in the NICOFE alloy.
Applicable Materials & Geometry
Section titled âApplicable Materials & Geometryâ| Research Requirement | 6CCVD Material Recommendation | Technical Advantage |
|---|---|---|
| High-Performance Abrasive (Synthetic Monocrystalline Grit) | High-Toughness Polycrystalline Diamond (PCD): For extreme wear applications like stone cutting, 6CCVD provides high-purity PCD wafers. | MPCVD PCD offers superior thermal stability and fracture toughness, leading to longer tool life and reduced diamond loss compared to standard synthetic grit. |
| Custom Pearl Dimensions (7.3 mm ĂExt, 5.0 mm ĂInt) | Custom Dimensions & Laser Cutting: 6CCVD manufactures PCD plates/wafers up to 125mm in size. We provide precision laser cutting services to produce custom segments, rings, or complex geometries required for multi-wire pearls. | Eliminates reliance on standard sizes, enabling rapid prototyping and optimization of pearl geometry for specific rock types and cutting speeds (28-32 m/s). |
| Matrix Bonding Enhancement (Addressing transition zone porosity/pull-out) | Advanced Metalization Services (Ti, W, Cu): The paper used Ti-coated diamond. 6CCVD offers internal metalization capabilities (Au, Pt, Pd, Ti, W, Cu) optimized for chemical bonding. | Custom Ti or W coatings applied under controlled conditions ensure superior carbide formation at the diamond-matrix interface, directly addressing the weak bond and âpull-outâ failure observed in the NICOFE composite. |
Customization Potential
Section titled âCustomization PotentialâThe success of next-generation diamond tools, particularly those utilizing low-cobalt matrices, hinges on optimizing the diamond-matrix interface. 6CCVDâs capabilities are perfectly aligned to support this optimization:
- Custom Metalization Recipes: We can develop and apply specific metalization stacks (e.g., Ti/W/Cu) to diamond surfaces to maximize wetting and chemical reactivity with Ni-Co-Fe<sub>3</sub>P-Sn-WC alloys during the 960°C Free Sintering cycle.
- Ultra-Precision Polishing: While not the primary focus of this abrasive application, 6CCVD offers polishing down to Ra < 5nm for inch-size PCD, ensuring high-quality surfaces for subsequent brazing or integration steps.
- Global Supply Chain: We offer global shipping (DDU default, DDP available) to ensure timely delivery of custom diamond materials for international research and manufacturing operations.
Engineering Support
Section titled âEngineering Supportâ6CCVDâs in-house PhD team specializes in the physics and chemistry of diamond-metal interfaces. We can assist researchers and engineers working on similar diamond wire saw composite projects by:
- Sintering Optimization Consultation: Providing expertise on how trace elements and sintering atmosphere (70% H<sub>2</sub> / 30% N<sub>2</sub>) interact with custom metalization layers to minimize porosity and maximize shear strength in the transition zone.
- Material Selection for Abrasive Environments: Guiding the selection between SCD and PCD grades based on the required wear resistance, thermal load, and impact toughness for cutting specific ornamental stones.
For custom specifications or material consultation, visit 6ccvd.com or contact our engineering team directly.
View Original Abstract
Objective: The main objective of this study is to manufacture a diamond composite with a metallic matrix based on Ni-Co-Fe3P-Sn-WC, using the Free Sintering process through cold uniaxial compaction, intended for the production of pearls for diamond wire saws, used in cutting ornamental stones. Theoretical Framework: The multi-wire technology represents an advancement in cutting ornamental stone blocks, allowing the simultaneous production of multiple slabs. Powder metallurgy is the predominant technique used in the manufacturing of pearls for diamond wire saws. Through testing, including scanning electron microscopy (SEM) and shear tests, it is possible to evaluate the alloyâs strength, diamond crystal adhesion, and failure behavior of the alloy. Methodology: The adopted methodology involves the processing and characterization of pearls for diamond wire saws, following the techniques of powder metallurgy. Initially, parametric calculations were performed using Excel, providing a basis for subsequent analyses. Diamond-coated pearls were produced with different proportions of constituent elements, and uniaxial compressive strength tests and microstructural characterization were conducted to evaluate the results. Results and Discussion: In the adhesion tests to the metal tube, the pearls produced with the NICOFE alloy showed similar performance to the commercial pearls âAâ and âB,â with satisfactory direct shear strength values. However, some point defects were observed, such as porosity in the transition zone, creating a weaker bond, negatively impacting the final strength of the composite. Analysis of the commercial samples indicated that diamond abrasion was not related to the composition of the sintered alloy. Research Implications: This research suggests significant economic and technological implications, such as the development and nationalization of technology for the ornamental stone industry. The use of the NICOFE alloy could strengthen the local industry by providing a viable and more accessible alternative for the production of diamond pearls. Originality/Value: The NICOFE blend presents technical advantages for manufacturing diamond wire pearls, highlighting the environmental benefits from reduced cobalt use and economic advantages by offering more accessible materials for the ornamental stone industry.