【公開日：2024.07.25】【最終更新日：2024.05.21】
課題データ / Project Data
課題番号 / Project Issue Number
23UT0240
利用課題名 / Title
熱電対埋設型工具の断面解析
利用した実施機関 / Support Institute
東京大学 / Tokyo Univ.
機関外・機関内の利用 / External or Internal Use
内部利用（ARIM事業参画者以外）/Internal Use (by non ARIM members)
技術領域 / Technology Area
【横断技術領域 / Cross-Technology Area】（主 / Main）加工・デバイスプロセス/Nanofabrication（副 / Sub）-
【重要技術領域 / Important Technology Area】（主 / Main）高度なデバイス機能の発現を可能とするマテリアル/Materials allowing high-level device functions to be performed（副 / Sub）-
キーワード / Keywords
sensor fabrication, temperature measurement, orthgonal cutting,センサ/ Sensor,蒸着・成膜/ Vapor deposition/film formation
利用者と利用形態 / User and Support Type
利用者名（課題申請者）/ User Name (Project Applicant)
Wang Chao
所属名 / Affiliation
東京大学 大学院工学系研究科
共同利用者氏名 / Names of Collaborators in Other Institutes Than Hub and Spoke Institutes
木崎通
ARIM実施機関支援担当者 / Names of Collaborators in The Hub and Spoke Institutes
利用形態 / Support Type
（主 / Main）機器利用/Equipment Utilization（副 / Sub）-
利用した主な設備 / Equipment Used in This Project
報告書データ / Report
概要（目的・用途・実施内容）/ Abstract (Aim, Use Applications and Contents)
An array of microscale thermocouples, which able to monitor the on-site temperature raising on tool-chip interface and tool-workpiece interface, was integrated on the cutting tool. The embedded sensors featured a fast response and online temperature measurement during the continuous metal machining process.
実験 / Experimental
Uncoated WC–Co cemented carbide, which is one of the most common types of cutting tool materials, was selected as the substrate for the integrate of our microsensor. To investigate the temperature gradient on the tool–chip contact area and on the relatively narrow tool–workpiece interface, four one-polar TCs with a diameter of 125 μm were embedded into the tool. A nickel-based chromel from the K-type TC produced by OMEGA Corp. was chosen as the positive electrode, while the adjacent tool material was set as the negative end. An insulation coating of 4 μm was deposited using the parylene coater SCS PDS2010. A schematic of the sensitivity test is shown in Fig. 1 (a). A 5 W CW laser with a 5 mm diameter was focused onto a 1 mm diameter spot and heated to a position close to the embedded TC. The temperature distribution during laser heating must be measured to record both the hot-junction temperature and pin temperature simultaneously. For this purpose, infrared thermography was employed, and it was set in the direction normal to the tool-rake surface at a safe distance. Blackbody paint with an emissivity of 0.94, which can tolerate temperatures of up to 500 °C, was uniformly coated on the measured surface to ensure that the emissivity maintained a stable and known value.
結果と考察 / Results and Discussion
The measured temperature data for the hot junction and pin are shown in Fig. 1(b). The Seebeck coefficient of the sensing system was then calculated. The results reveal that the Seebeck coefficient (i.e., the sensitivity of the embedded TC) remains almost unchanged regardless of the rising temperature and stabilizes at approximately 45 μV/°C. The dynamic response characteristics of the sensor-integrated tool were investigated with the application of a pulsed laser. The laser in the dynamic calibration generates a pulse temperature excitation with a width of 0.5s. The spot diameter, power, and heating position are consistent with those in the static calibration test. The maximum sampling frequency of the data acquisition device was 120 kHz, which was sufficient for collecting the output signal in the dynamic test. The response time corresponds to the rising time in the range 0% to 63.2% total step change of the output voltage. It is the most important dynamic parameter of the temperature sensor and reflects the response speed, especially in discontinuous cutting with a high rotating speed. As shown in Fig. 1(c), the duration of the output voltage rise from 0% to 63.2 % of the final voltage step, which is the response time of the sensor, was approximately 0.022s. The duration of the output voltage rise from 0% to 100% of the final voltage step, which is the stabilization time , was about 0.282s. It is demonstrated that the sensor-integrated tool has a sufficiently fast dynamic response. The time for the temperature measuremet value to stabilize is also fast enough for monitoring temperatures in the machining operations.
図・表・数式 / Figures, Tables and Equations
Fig. 1 (a) Schematic diagram of sensor calibration experiment (b) relationship between measure temperature in laser contact hot junction, pin of compensation wire and thermal induced voltage, calibration curve of integrated sensor (c) output signal of the integrated sensor caused by the pulse laser.
その他・特記事項（参考文献・謝辞等） / Remarks(References and Acknowledgements)
成果発表・成果利用 / Publication and Patents
論文・プロシーディング（DOIのあるもの） / DOI (Publication and Proceedings)
-
Chao Wang, Velocity plane-based analytical modeling for reconstructing temperature field at tool-chip/work interface, Precision Engineering, 88, 177-191(2024).
DOI: https://doi.org/10.1016/j.precisioneng.2024.02.003
口頭発表、ポスター発表および、その他の論文 / Oral Presentations etc.
特許 / Patents
特許出願件数 / Number of Patent Applications：0件
特許登録件数 / Number of Registered Patents：0件