Research of non-stationary thermal process in diamond-containing composite
At a Glance
Section titled âAt a Glanceâ| Metadata | Details |
|---|---|
| Publication Date | 2015-12-30 |
| Journal | Bulletin of Bryansk state technical university |
| Authors | Astemir A. Gutov, Astemir A. Gutov, Zalim N. Deunezhev, Zalim N. Deunezhev, Marianna R. Kardanova |
| Analysis | Full AI Review Included |
Technical Documentation & Analysis: Non-Stationary Thermal Processes in Diamond Composites
Section titled âTechnical Documentation & Analysis: Non-Stationary Thermal Processes in Diamond CompositesâThis document analyzes the research paper âRESEARCH OF NON-STATIONARY THERMAL PROCESS IN DIAMOND-CONTAINING COMPOSITEâ to provide technical specifications and identify specific material solutions offered by 6CCVD for advanced thermal management and abrasive applications.
Executive Summary
Section titled âExecutive SummaryâThe research focuses on computationally modeling the non-stationary thermal behavior of a diamond grain embedded in a polymer (Bakelite) matrix, typical of abrasive grinding tools.
- Core Problem: Inefficient utilization of diamond properties in abrasive tools due to low thermal stability and poor heat dissipation by the polymer matrix.
- Methodology: Non-linear 2D Finite Element Method (FEM) modeling of heat transfer in an ellipsoidal diamond grain (0.5 mm x 0.4 mm) under high heat flux.
- Key Finding (Steady-State): The final steady-state temperature (Tss) is critically dependent on the thermal conductivity ($\lambda$) of the polymer matrix.
- Key Finding (Transient): The time required to reach Tss (transition time, $t_c$) is primarily determined by the specific heat ($c$) of the matrix.
- Thermal Stress: Applied heat flux of $3.0 \times 10^{6}$ W/m² resulted in localized temperatures up to ~280 °C, highlighting the severe thermal environment faced by the diamond grain.
- Application: The model provides a basis for optimizing the design and operational parameters of diamond grinding wheels and other high-power density diamond composites.
Technical Specifications
Section titled âTechnical SpecificationsâThe following hard data points were extracted from the computational model parameters and results, focusing on the thermal and physical properties of the materials used.
| Parameter | Value | Unit | Context |
|---|---|---|---|
| Diamond Density ($\rho$) | 3520 | kg/m³ | At 20 °C |
| Diamond Thermal Conductivity ($\lambda$) | 146.5 | W/(m¡K) | At 20 °C (Used in model) |
| Diamond Specific Heat ($c$) | 502 | J/(kg¡K) | At 20 °C |
| Matrix (Bakelite) Density ($\rho$) | 1300 | kg/m³ | At 20 °C |
| Matrix (Bakelite) Thermal Conductivity ($\lambda$) | 0.18 | W/(m¡K) | Lowest value tested |
| Matrix (Bakelite) Specific Heat ($c$) | 1600 | J/(kg¡K) | Value used for $t_c$ calculation |
| Applied Heat Flux ($Q$) | 3.0 x 10✠| W/m² | Thermal load during cutting/grinding |
| Convective Heat Transfer Coefficient ($h$) | 5.0 x 10³ | W/(m²¡K) | Heat loss to environment |
| Diamond Grain Dimensions | 0.5 x 0.4 | mm | Ellipsoid axes used for modeling |
| Maximum Steady-State Temperature (Tss) | ~280 | °C | Observed in the matrix zone (A) with Bakelite ($\lambda=0.18$) |
| Transition Time ($t_c$) | ~11 | seconds | Time to reach Tss using Bakelite ($c=1600$) |
Key Methodologies
Section titled âKey MethodologiesâThe research utilized a computational approach to solve a non-linear heat transfer problem, focusing on the transient behavior of the diamond-polymer interface.
- Governing Equation: The 2D non-stationary heat conduction equation was solved in a non-linear formulation, accounting for the temperature dependence of thermal conductivity ($\lambda$) and specific heat ($c$).
- Modeling Scheme: A single ellipsoidal diamond grain (axes 0.5 mm and 0.4 mm) was modeled, embedded within a polymer matrix (Bakelite).
- Numerical Technique: The problem was solved using the Finite Element Method (FEM), implemented via specialized programs written in the Turbo-C algorithmic language.
- Thermal Load Application: Heat generation during cutting was simulated by applying a uniform specific heat flux ($Q = 3.0 \times 10^{6}$ W/m²) to the portion of the diamond contour directly contacting the workpiece.
- Boundary Conditions:
- Convective heat exchange with the surrounding environment was modeled using a heat transfer coefficient ($h = 5.0 \times 10^{3}$ W/(m²¡K)).
- Initial conditions were set to $T(x, y, 0) = 0$ (relative to ambient temperature $T_{\infty}$).
- Parametric Study: The simulation varied the matrix thermal conductivity ($\lambda$) (e.g., 0.18, 1.00, 1.50, 2.00 W/(m¡K)) and specific heat ($c$) (e.g., 100 to 2400 J/(kg¡K)) to determine their respective impacts on $T_{ss}$ and $t_c$.
6CCVD Solutions & Capabilities
Section titled â6CCVD Solutions & CapabilitiesâThe research demonstrates that thermal management is the limiting factor in high-performance diamond abrasive tools. 6CCVD provides high-quality MPCVD diamond materials and custom engineering services necessary to replicate this research, validate thermal models, and develop next-generation tools with superior thermal stability.
Applicable Materials for Thermal Management
Section titled âApplicable Materials for Thermal ManagementâThe paper cites a diamond thermal conductivity of 146.5 W/(m¡K) at 20 °C. 6CCVDâs high-purity Single Crystal Diamond (SCD) significantly exceeds this baseline, offering superior thermal performance critical for mitigating the observed 280 °C temperature spikes.
| 6CCVD Material | Application Focus | Key Specification Match |
|---|---|---|
| High-Purity SCD | Thermal spreaders, micro-tooling, high-power density applications. | Achieve thermal conductivities far exceeding 146.5 W/(m¡K) for maximum heat extraction from the cutting zone. |
| Optical Grade SCD | Applications requiring ultra-low surface roughness (Ra < 1 nm) combined with high thermal stability. | Ideal for thermal test structures where surface quality is paramount for interface modeling. |
| Polycrystalline Diamond (PCD) | Large-area abrasive tools, robust thermal substrates. | Provides mechanical toughness and high thermal conductivity over large areas (up to 125 mm diameter). |
| Boron-Doped Diamond (BDD) | Electrochemical sensing or electro-thermal modeling (if the composite requires conductive elements). | Available for specialized applications requiring both conductivity and thermal stability. |
Customization Potential for Research Replication and Extension
Section titled âCustomization Potential for Research Replication and Extensionâ6CCVDâs in-house manufacturing capabilities directly address the specific geometric and interface requirements necessary for advanced thermal modeling and tool development.
| Research Requirement | 6CCVD Customization Service | Technical Benefit |
|---|---|---|
| Specific Grain Geometry (0.5 mm x 0.4 mm) | Precision Laser Cutting & Etching | We can provide custom-shaped SCD or PCD plates/wafers, allowing researchers to create precise micro-scale thermal test structures that validate the ellipsoidal grain model. |
| Thermal Interface Modeling | Custom Metalization Services | We offer internal deposition of Au, Pt, Pd, Ti, W, and Cu. This is crucial for creating defined, low-resistance thermal contacts between the diamond and the matrix/sensor elements. |
| Large-Scale Composite Substrates | Large-Area PCD Wafers | We supply PCD plates up to 125 mm in diameter, with thicknesses ranging from 0.1 Âľm to 500 Âľm, suitable for industrial-scale composite development. |
| Surface Finish | Ultra-Smooth Polishing | SCD polishing to Ra < 1 nm and inch-size PCD polishing to Ra < 5 nm, minimizing surface scattering and ensuring consistent thermal contact. |
Engineering Support
Section titled âEngineering Supportâ6CCVDâs in-house PhD team specializes in the physical and thermal properties of MPCVD diamond. We offer consultation services to assist engineers and scientists in selecting the optimal diamond grade (SCD vs. PCD) and thickness (0.1 Âľm to 500 Âľm) for projects involving high heat flux ($3.0 \times 10^{6}$ W/m²) and non-stationary thermal modeling, such as Advanced Abrasive Tool Design or High-Power Thermal Spreading.
For custom specifications or material consultation, visit 6ccvd.com or contact our engineering team directly.
View Original Abstract
The computational modeling of temperature non-stationary fields in the system âdiamond-polymer matrixâ is carried out. The dependences of a steadystate temperature and time of transitional thermal process upon matrix thermal conductivity and heat capacity are defined.