A New Approach For Dressing Operation Monitoring Using Voltage Signals Via Impedance-Based Structural Health Monitoring
At a Glance
Section titled âAt a Glanceâ| Metadata | Details |
|---|---|
| Publication Date | 2018-02-11 |
| Journal | KnE Engineering |
| Authors | Pedro Oliveira, Rodrigo de Souza Ruzzi, Wenderson Nascimento Lopes, Felipe Aparecido Alexandre, FabrĂcio GuimarĂŁes Baptista |
| Institutions | Universidade Federal de UberlĂąndia, Universidade Estadual Paulista (Unesp) |
| Citations | 7 |
| Analysis | Full AI Review Included |
Diamond Tool Wear Monitoring via EMI: Technical Documentation & 6CCVD Solutions
Section titled âDiamond Tool Wear Monitoring via EMI: Technical Documentation & 6CCVD SolutionsâThis technical documentation analyzes the application of Electromechanical Impedance (EMI) monitoring for diamond dressing tool wear, aligning the research findings with the advanced Material and Engineering capabilities offered by 6CCVD.
Executive Summary
Section titled âExecutive SummaryâThis paper introduces a novel, low-cost structural health monitoring (SHM) methodology using time-domain voltage analysis from piezoelectric (PZT) transducers to assess the degradation of single-point diamond dressers.
- Core Achievement: Successfully demonstrated that time-domain voltage signals derived from the EMI method accurately monitor the progressive wear of a diamond dressing tool.
- Monitoring System: Utilized low-cost PZT (Lead Zirconate Titanate) ceramic transducers fixed to the dresser support to detect changes in mechanical impedance correlating to damage.
- Measurement Innovation: Focused on time-domain statistical metricsâspecifically RMSD (Root Mean Square Deviation) and CCDM (Correlation Coefficient Deviation Metric)âwhich proved highly sensitive to diamond damage progression.
- Experimental Context: Wear monitoring was performed on a natural diamond single-point dresser during the dry dressing of an Aluminum Oxide (Al2O3) grinding wheel.
- Damage Quantification: CCDM showed a linear, robust correlation with increasing diamond wear area, allowing for precise quantification of damage levels (Dano 1, Dano 2, Dano 3).
- Process Optimization: The study provides a simple, direct, and economically viable method for establishing a critical threshold for diamond tool replacement, ensuring consistent, high-value grinding operations.
Technical Specifications
Section titled âTechnical SpecificationsâHard data points extracted from the experimental methodology focusing on process parameters and sensor integration.
| Parameter | Value | Unit | Context |
|---|---|---|---|
| Grinding Wheel Material | Aluminum Oxide (38A150L6VH) | N/A | Conventional Grinding Wheel (NORTON) |
| Grinding Wheel Dimensions | 355.6 x 25.4 x 127 | mm | Diameter x Width x Bore |
| Diamond Tool Material Used | Natural Diamond | N/A | Single-point lapidated dresser |
| Dressing Velocity (vd) | 3.45 | mm/s | Constant speed during dry dressing trials |
| Dressing Depth of Cut (ad) | 40 | ”m | In-feed depth per pass |
| PZT Transducer Model | MURATA 7BB-20-6 | N/A | Low-cost piezo ceramic capsule |
| PZT Active Element Diameter | 14 | mm | Diameter of the internal piezo ceramic |
| PZT Active Element Thickness | 0.22 | mm | Thickness of the internal piezo ceramic |
| Excitation Amplitude (Vx) | 1 | V | Chirp signal used for PZT excitation |
| Series Resistance (Rs) | 2.2 | kΩ | Resistor in the EMI excitation circuit |
| Data Acquisition Rate | 250 | kS/s | Used by National Instruments NI USB-6221 DAQ |
| Measurement Repetitions | 3 | N/A | Average repetitions per impedance measurement for precision |
| Full Tool Wear Threshold | 300 | Passes | Defined as 100% estimated worn area |
Key Methodologies
Section titled âKey MethodologiesâThe following steps detail the experimental procedure for implementing the EMI-based monitoring system for diamond dresser wear:
- Sensor Installation: A low-cost PZT ceramic transducer was securely affixed to the diamond dresser support using a thin layer of cyanoacrylate adhesive, ensuring effective electromechanical coupling.
- Experimental Setup: The diamond dresser was mounted on a SulmecĂąnica RAPH 1055 flat tangential grinding machine, targeting dry dressing operations on a conventional Al2O3 grinding wheel.
- Dressing Cycle: The dressing parameters were set consistently: 40 ”m depth of dress and 3.45 mm/s constant velocity, performed without coolant to accelerate and standardize tool wear.
- Impedance Excitation: The PZT was excited with a 1 V amplitude chirp signal, monitored across a 2.2 kΩ series resistor, generating voltage signatures related to structural impedance.
- Data Collection: Voltage signals were recorded in the time-domain at intervals of 100 passes (PZT impedance measurements were averaged over 3 repetitions for reliability).
- Wear Quantification (Reference): Diamond wear area was independently measured using a digital microscope (DIGIMICRO 2.0, 20x magnification) and CAD software at 100, 200, and 300 passes.
- Signal Processing: Damage indices RMSD and CCDM were calculated from the time-domain voltage signals using MATLAB, referencing the signal from the initial, intact diamond tool (0 passes).
- Validation: The statistical indices (CCDM in particular) were verified against the known physical wear state of the diamond, establishing clear correspondence between signal magnitude changes and tool damage levels.
6CCVD Solutions & Capabilities: Enhancing SHM with Advanced Diamond Materials
Section titled â6CCVD Solutions & Capabilities: Enhancing SHM with Advanced Diamond MaterialsâThe success of any SHM system relies fundamentally on the stability and quality of the monitored tool. The paper used natural diamond, which inherently suffers from crystallographic inconsistencies. 6CCVDâs precision-engineered MPCVD diamond (SCD and PCD) provides the reliable foundation necessary to maximize the accuracy and longevity of EMI monitoring systems.
Applicable Materials
Section titled âApplicable MaterialsâTo replicate or extend this research, 6CCVD offers superior, highly uniform diamond materials, guaranteeing predictable wear behavior that enhances the reliability of SHM systems.
| Application/Requirement | 6CCVD Material Recommendation | Rationale |
|---|---|---|
| High-Precision Dressing | Single Crystal Diamond (SCD) | Superior crystallographic purity and hardness compared to natural diamond, leading to highly predictable wear rates and extended life. Ideal for precision monitoring applications. |
| Standard/Volume Dressing | Polycrystalline Diamond (PCD) Wafers | Excellent fracture toughness and abrasion resistance. Cost-effective in large sizes (up to 125mm) for applications where lower Ra finish is acceptable. |
| Integrated SHM | SCD Substrates (0.1”m - 500”m) | SCD thickness can be customized to match mechanical requirements of the dresser geometry, ensuring the toolâs structural integrity remains optimal for transducer response. |
Customization Potential
Section titled âCustomization PotentialâThe integration of PZT transducers requires specific geometric tolerances and robust bonding surfaces. 6CCVDâs specialized engineering services directly support the integration demands of EMI-based SHM systems.
- Precision Tool Blanks: 6CCVD supplies custom SCD plates and substrates in thicknesses up to 500 ”m, which can be tailored to the exact dimensions required for mounting in complex dresser holders, ensuring consistent mechanical coupling for PZT sensors.
- High-Precision Polishing: We offer Ra < 1nm polishing for SCD, which is crucial for maximizing tool life and maintaining consistent dressing performance. This high-quality surface minimizes initial noise in the EMI signal.
- Custom Metalization for Bonding: For permanent, reliable PZT bonding (as used in this research), 6CCVD offers internal metalization capabilities (Au, Pt, Pd, Ti, W, Cu). We can deposit precise, stable metal layers onto the diamond or diamond support structure, providing optimal chemical adhesion sites for SHM transducers.
- Custom Dimensions: Unlike standard suppliers, 6CCVD can laser cut and finish PCD plates up to 125mm, enabling engineers to design highly customized dressing tool geometries optimized for both performance and integrated sensor placement.
Engineering Support
Section titled âEngineering SupportâMonitoring the wear of diamond tools requires deep knowledge of diamond mechanics.
- 6CCVDâs in-house PhD engineering team specializes in the material science and mechanical performance of MPCVD diamond. We can assist customers in correlating EMI signatures (RMSD/CCDM) directly to the specific wear characteristics of SCD/PCD tools.
- We provide consultation on material selection (SCD vs. PCD) and tool design to optimize sensor placement for maximum signal sensitivity in dressing operation monitoring projects, ensuring the derived wear threshold (like the 300-pass limit in this study) is reliable and maximizing diamond tool ROI.
For custom specifications or material consultation, visit 6ccvd.com or contact our engineering team directly.
View Original Abstract
Among the methods used in structural health monitoring (SHM), the electromechanical impedance technique (EMI), which uses piezoelectric transducers of lead zirconate titanate (PZT), stands out for its low cost. This paper presents a new approach for monitoring of the dressing operation based on structural health monitoring from the digital processing of voltage signals based on the time-domain response of a PZT transducer by EMI method. Experimental tests of the dressing process were performed by using a single-point dresser equipped with a natural diamond. The voltage signals in the time-domain were collected in different damage levels using a measurements EMI System. By using damage metrics, it was possible to qualify different damage levels that the diamond suffered during the dressing operation, observing variations from the magnitude of the signals. The dressing operation is of utmost importance for the grinding process and the dresser wear negatively affects the result of the process, which owns high added value. In this way, this work contributes with a new monitoring tool which aims ensuring a consistent dressing operation.Keywords: Manufacturing process, automation, electromechanical impedance, dressing operation.