Tool Temperature in Titanium Drilling

2007 ◽  
Vol 129 (4) ◽  
pp. 740-749 ◽  
Author(s):  
Rui Li ◽  
Albert J. Shih
Keyword(s):  
Heat Transfer ◽  
Cutting Tools ◽  
Pure Titanium ◽  
Cutting Speed ◽  
Heat Transfer Analysis ◽  
Frictional Heat ◽  
Steady Increase ◽  
Commercially Pure Titanium ◽  
Tool Temperature ◽  
Inverse Heat Transfer

The spatial and temporal distribution of tool temperature in drilling of commercially pure titanium is studied using the inverse heat transfer method. The chisel and cutting edges of a spiral point drill are treated as a series of elementary cutting tools. Using the oblique cutting analysis of the measured thrust force and torque, the forces and frictional heat generation on elementary cutting tools are calculated. Temperatures measured by thermocouples embedded on the drill flank face are used as the input for the inverse heat transfer analysis to calculate the heat partition factor between the drill and chip. The temperature distribution of the drill is solved by the finite element method and validated by experimental measurements with good agreement. For titanium drilling, the drill temperature is high. At 24.4 m/min and 73.2 m/min drill peripheral cutting speed, the peak temperature of the drill reaches 480°C and 1060°C, respectively, after 12.7 mm depth of drilling with 0.025 mm feed per cutting tooth. The steady increase of drill temperature versus drilling time is investigated.

Characterization of Tissue Thermal Conductivity During a Tissue Joining Process

2016 ◽  
Author(s):  
Che-Hao Yang ◽  
Yang Liu ◽  
Wei Li ◽  
Roland K. Chen
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Tissue Sample ◽  
Heat Transfer Analysis ◽  
Vessel Sealing ◽  
Inverse Heat Transfer ◽  
Thermal Spread ◽  
Higher Temperature ◽  
Postoperative Problems ◽  
Joining Process

Electrosurgical vessel sealing, a tissue joining process, has been widely used in surgical procedures, such as prostatectomies for bleeding control. The heat generated during the process may cause thermal damages to the surrounding tissues which can lead to detrimental postoperative problems. Having better understanding about the thermal spread helps to minimize these undesired thermal damages. The purpose of this study is to investigate the changes of tissue thermal conductivity during the joining process. We propose a hybrid method combining experimental measurement with inverse heat transfer analysis to determine thermal conductivity of thin tissue sample. Instead of self-heating the tissue by the thermistor, we apply an external cold boundary on the other side of the tissue sample to stimulate a higher temperature gradient without denaturing the tissue in comparison to the heated method. The inverse heat transfer technique was then applied to determine the tissue thermal conductivity. Tissue thermal conductivity at different levels (0%, 25%, 50%, 75%, and 100%) of the joining process was measured. The results show a decreasing trend in tissue thermal conductivity with increasing joining level. When the tissue is fully joined, an average of 60% reduction in tissue thermal conductivity was found.

Thermal Conductivity and Specific Heat Evaluation of Tissue Using Laser

2020 ◽  
Vol 1002 ◽  
pp. 303-310
Author(s):  
Sudad Issam Younis ◽  
Haqi I. Qatta ◽  
Mohammed Jalal Abdul Razzaq ◽  
Khalid S. Shibib
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Thermal Properties ◽  
Specific Heat ◽  
Iterative Procedure ◽  
Input Data ◽  
Maximum Error ◽  
Heat Transfer Analysis ◽  
Long Wavelength ◽  
Inverse Heat Transfer

In this work, an inverse heat transfer analysis was used to determine thermal conductivity and specific heat of tissue using special iteration. A laser with a long wavelength was utilized to impose heat to the tissue. The heat that induced in the sample causes an increase in the temperature of a tissue which is measured by a thermocouple. The readings were used together with that analytically obtained from the solution of the heat equation in an iterative procedure to obtain the thermal properties of tissue. By using this method, accurate thermal conductivity and specific heat of tissue could be obtained. It was found that the maximum error in output result and the error in input data were in the same order and that there was a linear relationship between output and input errors.

A Study on Cutting Temperatures of Turning Stainless Steel with Chamfered Main Cutting Edge Nose Radius Tools

2009 ◽  
Author(s):  
Chung-Shin Chang
Keyword(s):  
Stainless Steel ◽  
Cutting Tools ◽  
Cutting Temperature ◽  
Cutting Edge ◽  
Heat Transfer Analysis ◽  
Nose Radius ◽  
Element Analysis ◽  
Inverse Heat Transfer ◽  
Frictional Forces ◽  
P Type

Temperatures of the carbide tip’s surface when turning stainless steel with a chamfered main cutting edge nose radius tool are investigated. The mounting of the carbide tip in the tool holder is ground to a nose radius as measured by a toolmaker microscope, and a new cutting temperature model developed from the variations in shear and friction plane areas occurring in tool nose situations are presented in this paper. The frictional forces and heat generated in the basic cutting tools are calculated using the measured cutting forces and the theoretical cutting analysis. The heat partition factor between the tip and chip is solved by the inverse heat transfer analysis, which utilizes the temperature on the P-type carbide tip’s surface measured by infrared as the input. The tip’s carbide surface temperature is determined by finite element analysis (FEA) and compared with temperatures obtained from experimental measurements. Good agreement demonstrates the accuracy of the proposed model.

Inverse Heat Transfer Analysis of Micro Heater Strength and Locations for Hyperthermia Treatment of Brain Tumors

2007 ◽  
Author(s):  
Maral Biniazan ◽  
Kamran Mohseni
Keyword(s):  
Heat Transfer ◽  
Brain Tumors ◽  
Transfer Problem ◽  
The Body ◽  
Least Square ◽  
Bioheat Transfer ◽  
Heat Transfer Analysis ◽  
Whole Body ◽  
Transient Temperature ◽  
Inverse Heat Transfer

Hyperthermia, also called thermal therapy or thermotherapy, is a type of cancer treatment in which the aim is to maintain the surrounding healthy tissue at physiologically normal temperatures and expose the cancerous region to high temperatures between 43°C–45°C. Several methods of hyperthermia are currently under study, including local, regional, and whole-body hyperthermia. In local hyperthermia, Interstitial techniques are used to treat tumors deep within the body, such as brain tumors. heat is applied to the tumor, usually by probes or needles which are inserted into the tumor. The heat source is then inserted into the probe. Invasive interstitial heating technique offer a number of advantages over external heating approaches for localizing heat into small tumors at depth. e. g interstitial technique allows the tumor to be heated to higher temperatures than external techniques. This is why an innovative internal hyperthermia research is being conducted in the design of an implantable microheater [1]. To proceed with this research we need complete and accurate data of the strength, number and location of the micro heaters, which is the objective of this paper. The location, strength, and number of implantable micro heaters for a given tumor size is calculated by solving an Inverse Heat Transfer Problem (IHTP). First we model the direct problem by calculating the transient temperature field via Pennies bioheat transfer equation. A nonlinear least-square method, modified by addition of a regularization term, Levenberg Marquardt method is used to determine the inverse problem [2].

Inverse heat transfer analysis for design and control of a micro-heater array

2016 ◽  
Vol 25 (9) ◽  
pp. 1259-1277
Author(s):  
Yixuan Tan ◽  
Chengjian Zheng ◽  
John T. Wen ◽  
Antoinette M. Maniatty
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Analysis ◽  
Inverse Heat Transfer ◽  
And Control
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