Measurement of Transient Tool-Internal Temperature Fields During Hard Turning by Insert-Embedded Thin Film Sensors

This paper presents a novel approach for obtaining thermal data from the close vicinity (70–700 μm) of the tool-workpiece interface while machining hardened steel. Arrays of microthin film C-type thermocouples with a junction size of 5 μm × 5 μm were fabricated by standard microfabrication methods and have been successfully embedded into polycrystalline cubic boron nitride (PCBN) using a diffusion bonding technique. Scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) were performed to examine material interactions at the bonding interface in order to determine optimal bonding parameters. Static and dynamic sensor performances have been characterized. The sensors exhibit excellent linearity up to 1300 °C, fast rise time of 150 ns, and sensitivity of ∼19 μV/ °C. The PCBN inserts instrumented with embedded thin film C-type thermocouples were successfully applied to measure internal tool temperatures as close as 70 μm to the cutting edge while machining hardened steel workpieces at industrially relevant cutting conditions. Correlations between temperature and cutting parameters have been established. The embedded microthin film sensor array provided unprecedented temporal and spatial resolution as well as high accuracy for microscale transient tool-internal temperature field measurements. Tool-internal temperature maps were generated from acquired data. In the frequency domain, obtained thermal data indicated the onset of regenerative machining chatter earlier and more effective than conventional force measurement by dynamometer.

[1]  N. F. Kazakov.  Diffusion bonding of materials , 1985 .

[2]  Xuejun Ren,et al.  Cutting temperatures in hard turning chromium hardfacings with PCBN tooling , 2004 .

[3]  Masami Masuko,et al.  Analytical Prediction of Three Dimensional Cutting Process—Part 1: Basic Cutting Model and Energy Approach , 1978 .

[4]  Eric Udd.  Fiber optic smart structures , 1996 .

[5]  Ichiro Inasaki,et al.  Tool Condition Monitoring (TCM) — The Status of Research and Industrial Application , 1995 .

[6]  Xiaochun Li,et al.  Embedding of micro thin film strain sensors in sapphire by diffusion bonding , 2007 .

[7]  Barney E. Klamecki,et al.  Force Sensors Embedded in Surfaces for Manufacturing and Other Tribological Process Monitoring , 1999 .

[8]  D. Polla,et al.  Experimental evaluation of MEMS strain sensors embedded in composites , 1999 .

[9]  Xudong Cheng,et al.  Study on Embedding and Integration of Microsensors Into Metal Structures for Manufacturing Applications , 2007 .

[10]  Xiaochun Li,et al.  Design, fabrication and characterization of metal embedded thin film thermocouples with various film thicknesses and junction sizes , 2006 .

[11]  Steven Y. Liang,et al.  Machining Process Monitoring and Control: The State-of-the-Art , 2004 .

[12]  Chun Liu,et al.  Single-step superfinish hard machining: Feasibility and feasible cutting conditions , 1996 .

[13]  Susan C. Mantell,et al.  Embedded Microelectromechanical Systems(MEMS) for Measuring Strain in Composites , 2000 .

[14]  Xiaochun Li,et al.  Batch Fabrication and Characterization of Micro-Thin-Film Thermocouples Embedded in Metal , 2006 .

[15]  Hans Kurt Tönshoff,et al.  Sensors in manufacturing , 2002 .

[16]  Hans Kurt Tönshoff,et al.  Cutting of Hardened Steel , 2000 .

[17]  David Dornfeld,et al.  Monitoring of Ultraprecision Machining Processes , 2003 .

[18]  Donald G. Krantz,et al.  Remotely queried wireless embedded microsensors in composites , 1997, Smart Structures.

[19]  A. Datta,et al.  Microfabrication and characterization of metal-embedded thin-film thermomechanical microsensors for applications in hostile manufacturing environments , 2006, Journal of Microelectromechanical Systems.