A New Method for Temperature Measurement to Determine the Temperature Variation in Cylindrical Grinding Contact Arc

2010 ◽  
Vol 139-141 ◽  
pp. 762-767
Author(s):  
Bei Zhi Li ◽  
Da Hu Zhu ◽  
Jing Zhu Pang ◽  
Zhen Xin Zhou ◽  
Jian Guo Yang
Keyword(s):  
Temperature Measurement ◽  
Temperature Variation ◽  
High Speed ◽  
New Method ◽  
Maximum Temperature ◽  
Depth Of Cut ◽  
Measured Temperature ◽  
Plunge Grinding ◽  
Temperature Signal ◽  
Contact Arc

Due to the difficulty in arrangement of thermocouples, temperature measurement in grinding presents a number of challenges, particularly in high speed cylindrical-plunge grinding. Based on existing literature, only single thermocouple is considered for measuring the maximum temperature in the grinding contact arc, without considering the overall temperature variation. In this paper, a new method for temperature measurement, named four K-type thermocouples, is proposed aslant along the direction of the width of workpiece which is developed for measuring the overall contact arc in high speed cylindrical-plunge grinding. It is shown that the temperature increases to the maximum with a sharp gradient, then decreases due to the strengthening of cooling effect and the decrease of depth of cut, which is consistent with previous study. The measured temperature signal reveals the generation rule and dissipation rule of grinding heat.

Temperature Measurement in High Speed Cylindrical-Plunge Grinding Using Thermocouple

2009 ◽  
Author(s):  
Dahu Zhu ◽  
Beizhi Li ◽  
Jingzhu Pang ◽  
Jianguo Yang ◽  
Dan Zhang
Keyword(s):  
Temperature Measurement ◽  
High Speed ◽  
Measurement Method ◽  
Maximum Temperature ◽  
Depth Of Cut ◽  
Measured Temperature ◽  
Plunge Grinding ◽  
Temperature Signal ◽  
Generation Rule ◽  
Contact Arc

Temperature measurement is employed for research in grinding and for process monitoring. Because of the difficulty in arrangement of thermocouples, temperature measurement in grinding presents a number of challenges, particularly in high speed cylindrical-plunge grinding. Based on existing literature, only one thermocouple is considered for measuring the maximum temperature in the grinding contact arc, without considering the overall temperature variation. In this paper, a new measurement method, named four K-type thermocouples are proposed aslant along the direction of the width of workpiece which is developed for measuring the overall contact arc in high speed cylindrical-plunge grinding. It is shown that the temperature increases to the maximum with a sharp gradient, then decreases due to the strengthening of cooling effect and the decrease of depth of cut, which is consistent with previous study. The measured temperature signal reveals the generation rule and dissipation rule of grinding heat. The influence of grinding parameters on the temperature is also discussed in detail in the paper.

Emissivity Compensated Pyrometry of the Substrate Surface During Movpe Growth of InxGa1−xAs1−yPy/InP Materials in Rotating Disc Reactors

1999 ◽  
Vol 607 ◽  
Author(s):  
J. Ramer ◽  
B. Patel ◽  
A. Patel ◽  
V. Boguslavskiy ◽  
A. Gurary
Keyword(s):  
Temperature Measurement ◽  
High Speed ◽  
Substrate Surface ◽  
Extreme Temperature ◽  
Temperature Sensitive ◽  
Measured Temperature ◽  
Material System ◽  
Rotating Disc ◽  
Production Scale ◽  
Movpe Growth

AbstractIn order to overcome some of the inherent difficulties with applying conventional pyrometry to production scale rotating disc MOVPE reactors, the in-situ technique of emissivity compensated pyrometry has been applied. Due to the extreme temperature sensitivity of epitaxial processes involving InxGa1−xAs1−yPy, this material system provides the optimum proving grounds for this technology. With this temperature measurement technique, we have developed a method for measuring the temperature of the substrate during MOVPE growth in high speed rotating disc reactors that does not require any modification to the reactor hardware. Real world testing, during the growth of complex epitaxial structures involving the highly temperature sensitive InxGa1−xAs1−yPy quaternary, indicates a very strong correlation between the measured temperature of the substrate during growth, and actual epitaxial wafer measurements after growth. This temperature measurement system can be used to maintain the wavelength of the InxGa1−xAs1−yPy quaternary materials within a range of 2 nm.

Three-Dimensional Finite Element Analysis in Cutting Temperature for High Speed Milling of Titanium Alloys

2011 ◽  
Vol 189-193 ◽  
pp. 2259-2263
Author(s):  
You Xi Lin ◽  
Cong Ming Yan
Keyword(s):  
Finite Element ◽  
Temperature Distribution ◽  
Titanium Alloys ◽  
High Speed ◽  
Three Dimensional ◽  
Cutting Temperature ◽  
Maximum Temperature ◽  
Depth Of Cut ◽  
High Speed Milling ◽  
Radial Depth

A three dimensional fully thermal-mechanical coupled finite element model had been presented to simulate and analyze the cutting temperature for high speed milling of TiAl6V4 titanium alloy. The temperature distribution induced in the tool and the workpiece was predicted. The effects of the milling speed and radial depth of cut on the maximum cutting temperature in the tool was investigated. The results show that only a rising of temperature in the lamella of the machined surface is influenced by the milling heat. The maximum temperature in the tool increases with increasing radial depth of cut and milling speed which value is 310°C at a speed of 60 m/min and increases to 740°C at 400m/min. The maximum temperature is only effective on a concentrated area at the cutting edge and the location of the maximum temperature moves away from the tool tip for higher radial depths of milling. The predicted temperature distribution during the cutting process is consistent with the experimental results given in the literature. The results obtained from this study provide a fundamental understanding the process mechanics of HSM of titanium alloys.

FEM Analysis of Temperature in High Speed Cutting of TiAl6V4 Alloys

2012 ◽  
Vol 522 ◽  
pp. 201-205
Author(s):  
You Xi Lin ◽  
Cong Ming Yan ◽  
Zheng Ying Lin
Keyword(s):  
Temperature Distribution ◽  
High Speed ◽  
Metal Cutting ◽  
Cutting Temperature ◽  
Fem Analysis ◽  
Element Model ◽  
Maximum Temperature ◽  
Depth Of Cut ◽  
Machined Surface ◽  
Radial Depth

mprovements in modeling and simulation of metal cutting processes are required in advanced manufacturing technologies. A three dimensional fully thermal mechanical coupled finite element model had been applied to simulate and analyze the cutting temperature for high speed milling of TiAl6V4 titanium alloy. The temperature distribution induced in the tool and the workpiece was predicted. The effects of the milling speed and radial depth of cut on the maximum cutting temperature in the tool was investigated. The results show that only a rising of temperature in the lamella of the machined surface is influenced by the milling heat. The maximum temperature in the tool increases with increasing radial depth of cut and milling speed which value is 310°C at a speed of 60 m/min and increases to 740°C at 400m/min. The maximum temperature is only effective on a concentrated area at the cutting edge and the location of the maximum temperature moves away from the tool tip for higher radial depths of milling. The predicted temperature distribution during the cutting process is consistent with the experimental results given in the literature. The results obtained from this study provide a fundamental understanding the process mechanics of HSM of TiAl6V4 titanium alloys.

scholarly journals Temperature evolution of the train brake disc during high-speed braking

2019 ◽  
Vol 11 (1) ◽  
pp. 168781401881956
Author(s):  
Zhizhong Wang ◽  
Jianmin Han ◽  
Xiaolong Liu ◽  
Zhiqiang Li ◽  
Zhiyong Yang ◽  
...  
Keyword(s):  
Finite Element ◽  
Temperature Distribution ◽  
Temperature Variation ◽  
Friction Surface ◽  
High Speed ◽  
Experimental Results ◽  
Temperature Evolution ◽  
Maximum Temperature ◽  
Brake Disc ◽  
In Situ Experiments

Temperature evolution of the train brake disc during high-speed braking was investigated using in situ experiments, theoretical analysis, and finite element modeling. The experimental results show that the temperature distribution on the friction surface experienced the formation of a hot ring first, then expansion and duration of the hot ring. Alternative hot spot and cold zone were observed on the friction surface, which is attributed to the local contact in the friction couple and heterogeneous heat dissipation condition in the disc. The corresponding maximum temperature in the disc increased rapidly first, kept stable then, and decrease slowly in the end. The one-dimensional heat conduction equation was applied to predict the maximum temperature variation and was found to be in agreement with the experimental results. Furthermore, the maximum temperature evolution and the temperature distribution of the disc at the braking time of 45 s were simulated by the finite element method, which is satisfactory. In additional, the temperature variation caused the corresponding fluctuation of instantaneous frictional coefficient and thermal stress distribution in the disc, which results in the thermal damages.

A new method used for high speed pseudo-random code generating

2014 ◽  
Author(s):  
Zhanfeng Zhao ◽  
Dong Zhang ◽  
Zhiquan Zhou
Keyword(s):  
High Speed ◽  
New Method ◽  
Random Code

Maximum Temperature Through a Yttrium Stabilized Zirconia Ceramic After Er,Cr:YSGG Laser Irradiation

2020 ◽  
Vol 02 ◽  
Author(s):  
Laurel Stringer ◽  
Sarah Malley ◽  
Darrell M. Hutto ◽  
Jason A. Griggs ◽  
Susana M. Salazar Marocho
Keyword(s):  
High Speed ◽  
Potential Method ◽  
Maximum Temperature ◽  
Zirconia Ceramic ◽  
Tooth Pulp ◽  
Control Group ◽  
Stabilized Zirconia ◽  
Significant Difference ◽  
Power Setting ◽  
Group A

Background: The most common approach to remove yttria stabilized zirconia (YSZ) fixed-dental prostheses (FDPs) is by means of diamond burs attached to a high-speed handpiece. This process is time-consuming and destructive. The use of lasers over mechanical instrumentation for removal of FDPs can lead to efficient and predictable restoration retrievability. However, the heat produced might damage the tooth pulp (>42˚C). Objective: The purpose of this study was to determine the maximum temperature (T) reached during the use of different settings of the erbium, chromium:yttrium-scandium-gallium-garnet Er,Cr:YSGG laser through a YSZ ceramic. Methods: YSZ slices (1 mm thick) were assigned into 7 groups. For the control group, a diamond bur was used to cut a 1 mm groove into the YSZ slices. For the 6 experimental groups, the laser was operated at a constant combination of 33% water and 66% air during 30 s with two different power settings (W) at three frequencies (PPS), as follows (W/PPS): 2.5/20, 2.5/30, 2.5/45, 4.5/20, 4.5/30, 4.5/45. The T through the YSZ slice was recorded in degrees Celsius by using a digital thermometer with a K thermocouple. Results: The median T of the control group was 26.5˚C. The use of 4.5 W resulted in the median T (˚C) of 44.2 at 20 PPS, 53.3 at 30 PPS, and 58.9 at 45 PPS, while 2.5 W showed 34.6, 31.6, and 25.0 at 20, 30, and 45 PPS, respectively. KruskalWallis one-way ANOVA showed that within each power setting, the T was similar. The high power and lowest frequency (4.5/20) showed no significant difference from the 2.5 W settings and the control group. Conclusion: The lower power setting (2.5 W) is a potential method for the use of the Er,Cr:YSGG laser to debond YSZ structures. The higher power (4.5 W) with high frequencies (30 and 45 PPS) is unsuitable.

scholarly journals A New Method to Verify the Measurement Speed and Accuracy of Frequency Modulated Interferometers

2021 ◽  
Vol 11 (13) ◽  
pp. 5787
Author(s):  
Toan-Thang Vu ◽  
Thanh-Tung Vu ◽  
Van-Doanh Tran ◽  
Thanh-Dong Nguyen ◽  
Ngoc-Tam Bui
Keyword(s):  
Phase Change ◽  
High Speed ◽  
Measurement Accuracy ◽  
Slow Motion ◽  
New Method ◽  
Virtual Displacement ◽  
Electro Optic ◽  
Lock In ◽  
Speed And Accuracy ◽  
Electro Optic Modulator

The measurement speed and measurement accuracy of a displacement measuring interferometer are key parameters. To verify these parameters, a fast and high-accuracy motion is required. However, the displacement induced by a mechanical actuator generates disadvantageous features, such as slow motion, hysteresis, distortion, and vibration. This paper proposes a new method for a nonmechanical high-speed motion using an electro-optic modulator (EOM). The method is based on the principle that all displacement measuring interferometers measure the phase change to calculate the displacement. This means that the EOM can be used to accurately generate phase change rather than a mechanical actuator. The proposed method is then validated by placing the EOM into an arm of a frequency modulation interferometer. By using two lock-in amplifiers, the phase change in an EOM and, hence, the corresponding virtual displacement could be measured by the interferometer. The measurement showed that the system could achieve a displacement at 20 kHz, a speed of 6.08 mm/s, and a displacement noise level < 100 pm//√Hz above 2 kHz. The proposed virtual displacement can be applied to determine both the measurement speed and accuracy of displacement measuring interferometers, such as homodyne interferometers, heterodyne interferometers, and frequency modulated interferometers.

Study on Edge Contact Area and Surface Integrity of Workpiece in Point Grinding Process

2009 ◽  
Vol 407-408 ◽  
pp. 577-581
Author(s):  
Shi Chao Xiu ◽  
Zhi Jie Geng ◽  
Guang Qi Cai
Keyword(s):  
Surface Integrity ◽  
Contact Area ◽  
High Speed ◽  
Ground Surface ◽  
Depth Of Cut ◽  
Grinding Wheel ◽  
Grinding Process ◽  
Edge Contact ◽  
Cylindrical Grinding ◽  
Theoretic Foundations

During cylindrical grinding process, the geometric configuration and size of the edge contact area between the grinding wheel and workpiece have the heavy effects on the workpiece surface integrity. In consideration of the differences between the point grinding and the conventional high speed cylindrical grinding, the geometric and mathematic models of the edge contact area in point grinding were established. Based on the models, the numerical simulation for the edge contact area was performed. By means of the point grinding experiment, the effect mechanism of the edge contact area on the ground surface integrity was investigated. These will offer the applied theoretic foundations for optimizing the point grinding angles, depth of cut, wheel and workpiece speed, geometrical configuration and size of CBN wheel and some other grinding parameters in point grinding process.

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