Fundamental investigations on temperature development in ultra-precision turning
At a Glance
Section titled âAt a Glanceâ| Metadata | Details |
|---|---|
| Publication Date | 2025-01-01 |
| Journal | The International Journal of Advanced Manufacturing Technology |
| Authors | Julian Polte, Toni Hocke, Kai ThiĂen, E. Uhlmann |
| Institutions | Fraunhofer Institute for Production Systems and Design Technology, Technische UniversitÀt Berlin |
| Citations | 2 |
| Analysis | Full AI Review Included |
Technical Documentation & Analysis: Ion-Implanted BDD for Ultra-Precision Sensing
Section titled âTechnical Documentation & Analysis: Ion-Implanted BDD for Ultra-Precision SensingâThis document analyzes the research paper âFundamental investigations on temperature development in ultra-precision turningâ and correlates its findings and material requirements with the advanced capabilities of 6CCVD, specializing in MPCVD diamond solutions.
Executive Summary
Section titled âExecutive SummaryâThe research successfully developed and validated a highly sensitive cutting edge temperature measurement system using ion-implanted Boron-Doped Single Crystal Diamond (SCD) tools for Ultra-Precision Turning (UPT).
- High Sensitivity & Accuracy: Demonstrated exceptional resolution accuracy (0.29 °C to 0.39 °C) and low total measurement uncertainty (0.098 °C) in the cutting zone.
- Rapid Dynamic Monitoring: Achieved fast response times (420 ms to 440 ms), crucial for dynamic monitoring of high-speed UPT processes.
- Superior Doping Method: Ion implantation enabled precise, partial boron doping (150 nm depth) close to the cutting edge (90 ”m distance), overcoming the structural imperfections and brittleness associated with holistic CVD/HPHT doping.
- Broad Material Compatibility: The system successfully measured cutting temperatures during the machining of both plastic (PMMA, PSU, PC) and electrically conductive metallic materials (Brass, Aluminum, Copper).
- Foundation for Smart Manufacturing: The results provide fundamental data correlating cutting temperatures with chip formation mechanisms, serving as a basis for self-optimizing and self-learning UPT machine tools.
- Key Finding: Highest measured cutting temperature was 50.18 °C (Brass machining) and 44.25 °C (PMMA roughing), confirming the need for high-thermal-conductivity diamond tools.
Technical Specifications
Section titled âTechnical SpecificationsâThe following hard data points were extracted from the experimental results and simulation parameters:
| Parameter | Value | Unit | Context |
|---|---|---|---|
| Resolution Accuracy (aR) | 0.29 - 0.39 | °C | During UPT machining (20 °C †$\theta$C,M †45 °C) |
| Total Measurement Uncertainty (uM) | 0.098 | °C | Sensor accuracy in analyzed process area |
| Response Time (tR) | 420 - 440 | ms | Rake angle range 0° †$\gamma$0 †-30° |
| Doping Material | Boron (p-type) | N/A | Ion-implanted Single Crystal Diamond |
| Doping Level (dlev) | 4E15 | ions/cm2 | Used for experimental SCD tools |
| Doping Depth (ddep) | 150 | nm | Precise control via ion implantation |
| Doping Length (dlen) | 0.4 | mm | Used for experimental SCD tools |
| SCD Tool Corner Radius (r$\epsilon$) | 1.5 | mm | Used for all experimental tools |
| Max Measured Temp (Brass) | 42.28 | °C | vc = 350 m/min, ap = 5 ”m, f = 5 ”m |
| Max Measured Temp (PMMA) | 50.18 | °C | Roughing (vc=350 m/min, ap=35 ”m, f=35 ”m, $\gamma$0=-30°) |
| Diamond Thermal Conductivity ($\lambda$) | 2200 | W/(mK) | Input parameter for FEM simulation |
| Diamond Density ($\rho$) | 3516 | kg/m3 | Input parameter for FEM simulation |
Key Methodologies
Section titled âKey MethodologiesâThe experimental success hinges on the precise preparation and integration of the SCD sensor tool:
- Ion Implantation Doping: Single Crystal Diamond (SCD) tools were partially and specifically doped with Boron (p-type) using a 100-keV implanter and a SNICS ion source. This physical process ensures dopants are fully embedded, preventing electrical short circuits when machining conductive materials.
- Precise Doping Geometry: Specific doping structures (44 ”m width, 420 ”m length, 150 nm depth) were implemented on the rake face (A$\gamma$) at a controlled distance (dc) of 90 ”m from the cutting edge.
- Micro-Electronic Contacting: Two additional boron structures (200 ”m width, 2.16 mm length) were implanted up to the graphitization limit (dlev = 2E16 ions/cm2) to achieve suitable electrical conductivity ($\kappa$) for micro-electronic connection.
- Sensor Calibration: The temperature-dependent electrical resistance (Rel) was calibrated using a high-precision WaferTherm chuck system across a range of 20 °C to 140 °C.
- Integrated UPT Setup: The ion-implanted BDD SCD sensor system was fully embedded in a monolithic ceramic (Macor) tool holder and integrated into a MOORE NANOTECH 350 FG ultra-precision machine tool.
- Thermal Simulation: A validated 3D-Finite Element Method (FEM) thermal-transient analysis was used to correct the temperature difference caused by the 90 ”m distance between the doping area and the actual cutting edge (dc = 0 ”m).
6CCVD Solutions & Capabilities
Section titled â6CCVD Solutions & Capabilitiesâ6CCVD is uniquely positioned to supply the high-purity, custom-engineered diamond materials required to replicate, validate, and extend this critical research into self-optimizing ultra-precision machining systems.
Applicable Materials
Section titled âApplicable MaterialsâThe core requirement of this research is a high-quality, low-defect SCD substrate that can withstand subsequent ion implantation or be grown with precise doping control.
| Research Requirement | 6CCVD Solution | Technical Advantage |
|---|---|---|
| Base Tool Material | Optical Grade Single Crystal Diamond (SCD) | High purity and low defect density ensure maximum thermal conductivity ($\lambda$ > 2000 W/(mK)), crucial for heat dissipation and stable sensor performance. |
| Sensor Material | Custom Boron-Doped Diamond (BDD) Substrates | We offer BDD materials with precise control over doping concentration (dlev) and thickness (0.1 ”m - 500 ”m), enabling researchers to explore alternative doping methods (e.g., in-situ CVD doping) or optimize ion-implantation recipes. |
| Tool Substrates | SCD Substrates up to 10 mm Thickness | Provides robust material for manufacturing the large, complex tool geometries (hD = 2 mm, wD = 4.25 mm) required for integration into monolithic tool holders. |
Customization Potential
Section titled âCustomization PotentialâThe success of the ion-implanted sensor relies heavily on precise geometry, placement, and electrical contactingâall areas where 6CCVD offers specialized, in-house capabilities.
- Custom Dimensions and Shaping: The paper utilized SCD tools with a 1.5 mm corner radius (r$\epsilon$). 6CCVD provides custom laser cutting and shaping services to produce plates and wafers up to 125 mm (PCD) or custom SCD tools, ensuring the exact geometric specifications (e.g., rake angle $\gamma$0, clearance angle $\alpha$0) required for UPT research are met.
- Precision Metalization for Sensing: The sensor requires two specific contacting surfaces (90 ”m x 90 ”m) with high electrical conductivity. 6CCVD offers internal, high-precision metalization capabilities (Au, Pt, Pd, Ti, W, Cu) necessary to create reliable micro-electronic contacts on the doped diamond surface, ensuring low resistance and stable signal acquisition.
- Ultra-Smooth Polishing: To maintain the integrity of the cutting edge and minimize friction-induced temperature fluctuations, the SCD tools require ultra-low roughness. 6CCVD guarantees polishing quality of Ra < 1 nm for SCD, exceeding the requirements for ultra-precision optical machining.
Engineering Support
Section titled âEngineering SupportâThis research is highly specialized, focusing on the electro-sensory properties and thermal-mechanical coupling in micro-cutting.
- Expert Consultation: 6CCVDâs in-house PhD engineering team specializes in CVD growth parameters, doping optimization, and material selection for advanced electro-thermal sensing applications. We can assist researchers in optimizing material properties to replicate or extend this Ultra-Precision Diamond Tool Sensing project, particularly concerning the trade-offs between doping level, electrical resistance, and thermal inertia (Cth).
- Global Supply Chain: We offer reliable global shipping (DDU default, DDP available) to ensure rapid delivery of custom diamond materials to research facilities worldwide, supporting time-sensitive experimental works.
For custom specifications or material consultation, visit 6ccvd.com or contact our engineering team directly.
View Original Abstract
Abstract Ultra-precision machining represents a key technology for manufacturing optical components in medical, aerospace and automotive industry. Dedicated single crystal diamond tools enable the production of innovative optical surfaces and components with high dimensional accuracies and low surface roughness values in a wide range of airborne sensing and imaging applications concerning space telescopes, fast steering mirrors, laser communication and high-energy laser systems. Despite the high mechanical hardness of single crystal diamonds, temperature-induced wear of the diamond tools occurs during the process. In order to increase the economic efficiency of ultra-precision turning, the characterisation and interpretation of cutting temperatures are of utmost importance. According to the state-of-the-art, there are no precise methods for online temperature monitoring during the process at the cutting edge with regard to the requirements for resolution accuracy, response time and accessibility to the cutting edge. For this purpose, a dedicated cutting edge temperature measurement system based on ion-implanted boron-doped single crystal diamonds as a highly sensitive temperature sensor for ultra-precision turning was developed. To enable highly sensitive temperature measurements, ion implantation was used for partial and specific boron doping close to the cutting edge of single crystal diamond tools. Within the investigations, a resolution accuracy of 0.29 °C †a R †0.39 °C could be proven for the developed cutting edge temperature measurement system. In addition, a total measurement uncertainty of u M = 0.098 °C was determined for the sensor accuracy a S in the investigated process area. For a rake angle range of 0° †γ 0 †â30°, reaction times of 420 ms †t R †440 ms were further determined. Using the developed cutting edge temperature measurement system enables a holistic view of the temperature development during ultra-precision machining, whereby a correlation between the measured cutting temperatures and the chip formation mechanisms depending on the applied process parameters could be identified. Within the investigations, the highest measured temperatures of Ï M = 50.18 °C and simulated maximum temperatures of Ï S,max = 183.12 °C were determined at a cutting speed of v c = 350 m/min, a cutting depth of a p = 35 ”m as well as a feed of f = 35 ”m using a rake angle of Îł 0 = â30°. The most uniform chips with the smoothest surfaces were identified within the chip analysis using a cutting speed of v c = 50 m/min, a cutting depth of a p = 5 ”m and a feed of f = 35 ”m with a measured temperature of Ï M = 21.30 °C and a simulated temperature of Ï S = 38.47 °C in the examined finishing area. According to the results, it was also shown that the cutting edge temperature measurement system with ion-implanted diamonds can be used for both electrically conductive and non-conductive materials. This provides the fundamentals for further research works to identify the complex temperature-induced wear behaviour of single crystal diamonds in ultra-precision turning and serves as the basis for self-optimising and self-learning ultra-precision machine tools.