Transient Temperature Measurement in Nanosecond Pulsed Laser Micro Drilling by Using Micro Thin Film Thermocouples

2005 ◽  
Author(s):  
Hongseok Choi ◽  
Xiaochun Li
Keyword(s):  
Thin Film ◽  
Numerical Models ◽  
Pulsed Laser ◽  
Transient Temperature ◽  
Fundamental Study ◽  
Nanosecond Pulsed Laser ◽  
Micro Drilling ◽  
Thin Film Thermocouples ◽  
Transient Thermal ◽  
Thermal Phenomena

It is of fundamental interest to investigate the complicated and transient thermal phenomena near the nanosecond pulsed laser-material interaction region. While numerous analytic and numerical models have been developed, little experimental results are available for a solid understanding of transient thermal phenomena in nanosecond pulsed laser micro drilling. In this paper, micro thin film thermocouples were fabricated on electroplated nickel substrates to study the transient temperature variations during laser micro drilling. Transient temperatures were successfully measured with superior temporal and spatial resolutions for the fundamental study of the nanosecond pulsed laser micro drilling. The in-situ measured data can be used to improve existing analytical and numerical models.

Transient Surface Temperature Measurement With Micro Sensors for Nanosecond Pulsed Laser Micromachining of Nickel

2006 ◽  
Author(s):  
Hongseok Choi ◽  
Xiaochun Li
Keyword(s):  
Laser Energy ◽  
Numerical Models ◽  
Pulsed Laser ◽  
Laser Micromachining ◽  
Measured Data ◽  
Time Resolved ◽  
Nanosecond Pulsed Laser ◽  
Thin Film Thermocouples ◽  
Transient Thermal ◽  
Thermal Phenomena

In order to investigate and understand the complicated transient thermal phenomena in laser micro processing, it is essential to accurately measure time-resolved temperatures of the workpiece. Micro thin film thermocouples with a micrometer spatial and nanosecond temporal resolution were fabricated on electroplated nickel workpieces to measure transient surface temperatures in nanosecond pulsed laser micromachining by ablation. Transient temperatures were successfully measured, and the effect of laser energy fluences on the peak temperatures was experimentally investigated. This study demonstrates that the micro TFTCs can be useful in measuring the transient temperatures on the workpiece during laser micromachining, and the measured data can be utilized to validate and improve existing analytical and numerical models.

PCB‐integrated thin film thermocouples for transient temperature measurement

2016 ◽  
Vol 52 (13) ◽  
pp. 1140-1141 ◽  
Author(s):  
WenLian Wang ◽  
Hui Zhang ◽  
XiaoJun Du ◽  
YouYi Sun
Keyword(s):  
Thin Film ◽  
Temperature Measurement ◽  
Transient Temperature ◽  
Thin Film Thermocouples

Transformation in iron–platinum thin film via nanosecond pulsed laser irradiation

2017 ◽  
Vol 109 ◽  
pp. 46-49 ◽  
Author(s):  
Yutaka Yoshida ◽  
Shigeo Yatsu ◽  
Seiichi Watanabe ◽  
Akira Yamauchi ◽  
Jun-ichi Shibano
Keyword(s):  
Thin Film ◽  
Laser Irradiation ◽  
Pulsed Laser ◽  
Iron Platinum ◽  
Nanosecond Pulsed Laser ◽  
Platinum Thin Film ◽  
Pulsed Laser Irradiation

Fabrication and Calibration of Cu-Ni Thin Film Thermocouples

2012 ◽  
Vol 512-515 ◽  
pp. 2068-2071 ◽  
Author(s):  
Hang Guo ◽  
Jun Ying Jiang ◽  
Jia Xing Liu ◽  
Zhi Hua Nie ◽  
Fang Ye ◽  
...  
Keyword(s):  
Thin Film ◽  
Silicon Dioxide ◽  
Temperature Sensor ◽  
Dynamic Performance ◽  
Protective Layer ◽  
High Sensitivity ◽  
Transient Temperature ◽  
Thin Film Thermocouple ◽  
Thin Film Thermocouples ◽  
Metal Layers

Thin film thermocouples (TFTCs) have vast vistas owing to their advantages, such as thin junction, small volume, fast response rate, high sensitivity and so on. In this investigation, a transient temperature sensor of TFTCs was fabricated to measure the surface transient temperature by vacuum coating technology. Silicon dioxide was selected as insulating substrate, the overall dimension of which was 8 mm long, 8 mm wide, and 0.1 mm thick. Two different metal layers were sandwiched between silicon dioxide 2 insulating substrate and silicon dioxide protective layer: cuprum and nickel films, which were 0.08 μm thick. TFTCs consist of 13 Cu-Ni junctions, which are connected in series. The whole TFTCs area is 4.6mm × 4.6 mm. The aggregate thickness of the transient temperature sensor is 0.17 μm. To protect Cu and Ni films, a silicon dioxide layer thickness of 0.01 μm was evaporated on metal layers excluding terminal points. This research carried out static and dynamic calibration to TFTCs. The Seebeck coefficient of the thin film thermocouple is 0.83843 μV/°C. The dynamic performance of TFTCs exhibited dynamic behavior corresponding to the heat flux change on the surface of thin film thermocouple.

Tool Embedded Thin Film Microsensors for Monitoring Thermal Phenomena at Tool-Workpiece Interface During Machining

2011 ◽  
Vol 133 (2) ◽  
Author(s):  
Dirk Werschmoeller ◽  
Kornel Ehmann ◽  
Xiaochun Li
Keyword(s):  
Thin Film ◽  
Cutting Temperature ◽  
Temperature Data ◽  
Temperature Fields ◽  
Thermal Sensors ◽  
Monitoring And Control ◽  
Machining Processes ◽  
Film Sensor ◽  
Fundamental Study ◽  
Thermal Phenomena

Existing thermal sensors for machining processes are having difficulties to reliably provide high spatial and temporal resolutions for monitoring and control of the dynamic thermal phenomena at the tool-workpiece interface during machining. This paper presents a novel approach to obtain transient tool internal temperature data reliably from a very close distance to the tool-workpiece interface. An array of nine microthin film thermocouples, fabricated using standard microfabrication methods, has been embedded into polycrystalline cubic boron nitride (PCBN) cutting inserts by means of diffusion bonding. Scanning electron microscopy was performed to examine thin film sensor and host material interactions at the bonding interface and to determine optimal bonding parameters. The thin film microthermal sensors were statically and dynamically characterized by heating in a tube furnace and application of pulsed laser radiation. The embedded thin film thermal sensors exhibit good linearity, sensitivity, and extremely fast response time. The instrumented PCBN inserts were applied in machining of aluminum alloy 6061 disks at various cutting speeds and feed rates. Embedded into the PCBN inserts at numerous distances of 75–450 μm from tool rake face and 100–500 μm from tool flank face, these microsensors enabled the sensing of transient cutting temperature fields with high spatial and temporal resolutions. The temperature data obtained during cutting demonstrate the functionality of the tool embedded microthermal sensors and their value for fast, accurate, and reliable monitoring, which will be of significance for both fundamental study and in-process control of machining operations.

Sign in / Sign up

Export Citation Format

Share Document