Study on Acoustic Emission in the Grinding Process Automation

1999 ◽  
Author(s):  
Ming Chen ◽  
Bing-Yuan Xue

Abstract Comprehensive experiments have been conducted to investigate the monitoring technique for grinding process automation with acoustic emission (AE) signal. The AE signal generated during the grinding process is analyzed to determine its sensitivity to process. The detection of contact between the grinding wheel and workpiece and in-process prediction of grinding burn have been discussed in sequence. The results have been obtained as follows: (1) AE contact detector can save the non-machine time remarkably, thus high efficiency is available. (2) An effective intelligent sensing system has been developed and grinding burn can predicted. As mentioned above, AE technique has found wide applications in the grinding process automation.

2013 ◽  
Vol 690-693 ◽  
pp. 2442-2445 ◽  
Author(s):  
Hao Lin Li ◽  
Hao Yang Cao ◽  
Chen Jiang

This work presents an experiment research on Acoustic emission (AE) signal and the surface roughness of cylindrical plunge grinding with the different infeed time. The changed infeed time of grinding process is researched as an important parameter to compare AE signals and surface roughnesses with the different infeed time in the grinding process. The experiment results show the AE signal is increased by the increased feed rate. In the infeed period of the grinding process, the surface roughness is increased at first, and then is decreased.


2020 ◽  
Vol 10 (22) ◽  
pp. 8240
Author(s):  
Jiaoyan Huang ◽  
Aiguo Xia ◽  
Shenao Zou ◽  
Cong Han ◽  
Guoan Yang

Effective and accurate diagnosis of engine health is key to ensuring the safe operation of engines. Inlet distortion is due to the flow or the pressure variations. In the paper, an acoustic emission (AE) online monitoring technique, which has a faster response time compared with the ordinary vibration monitoring technique, is used to study the inlet distortion of an engine. The results show that with the deterioration of the inlet distortion, the characteristic parameters of AE signals clearly evolve in three stages. Stage I: when the inlet distortion J ≤ 30%, the characteristic parameters of the AE signal increase as J increases and the amplitude saturates at J = 23%, faster than the other three parameters (the strength, the root mean square (RMS), and the average signal level (ASL)). Stage II: when the inlet distortion 30% < J ≤ 43.64%, all the parameters saturate with only slight fluctuations as J increases and the engine works in an unstable statue. Stage III: when the inlet distortion J > 43.64%, the engine is prone to surge. Furthermore, an intelligent recognition method of the engine inlet distortion based on a unit parameter entropy and the back propagation (BP) neural network is constructed. The recognition accuracy is as high as 97.5%, and this method provides a new approach for engine health management.


2005 ◽  
Vol 291-292 ◽  
pp. 207-212 ◽  
Author(s):  
Hitoshi Ohmori ◽  
Shao Hui Yin ◽  
Wei Min Lin ◽  
Yoshihiro Uehara ◽  
Shinya MORITA ◽  
...  

Metal bonded diamond grinding wheels are widely used in the grinding process, especial in ELID grinding. However, truing is difficult owing to the high toughness of metal bond materials and high hardness of diamond abrasives. To realize high precision and high-efficiency truing, we propose a new micro-truing method consisting of electro-discharge truing and electrolysis-assisted mechanical truing in this paper. The process principle and fundamental experimental results are introduced, and the truing performance is discussed. Research results show that the proposed new method is effective for truing metal bonded diamond grinding wheels.


2018 ◽  
Vol 3 (1) ◽  
pp. 414
Author(s):  
Felipe Aparecido Alexandre ◽  
Martin Antonio Aulestia Viera ◽  
Pedro Oliveira Conceição Junior ◽  
Leonardo Simões ◽  
Wenderson Nascimento Lopes ◽  
...  

Grinding is a high-precision, high-value-added finishing process as it is usually the last stage of the manufacturing chain. However, unsatisfactory results may occur, mainly due to changes in the microstructure of the ground workpiece. Such changes are caused by the high temperatures involved in the process due to the grinding conditions in which the part was subjected. In this way, the main objective of this work is the monitoring of the grinding process in order to detect changes in the signal and to relate them with damage occurred in the ground workpiece. The tests were carried out on a surface grinding machine, aluminum oxide grinding wheel and ABNT 1045 steel parts. Metallography was performed on the parts for a more further analysis of their microstructure. The recording of signals was obtained at a sample rate of 2 MHz through an acoustic emission sensor (AE). A frequency study for the selection of the best frequency bands that characterize damage occurred in the ground workpiece. The event counts statistic was applied to the filtered signal in the chosen frequency bands. The results of this work show that the grinding conditions influence the signal and, therefore, its frequency spectrum.Keywords: Manufacturing process; automation, monitoring; grinding process; acoustic emission, damage detection


Author(s):  
Fritz Klocke ◽  
Heiko Schlattmeier

Instances of damage to discontinuous form ground and surface-hardened gears, especially of large scale, have recently increased. This damage may be attributed partly to a faulty grinding process with negative effects on the surface zones and the surface properties. In addition to its high accuracy, discontinuous form grinding is characterized by high material removal because of the line contact between grinding wheel and tooth flank. The efficiency and reliability of the process are affected not only by the use of optimized grinding wheel specifications and machining parameters, but also by the risk of local surface zone damage in the form of grinding burn on the tooth flank. The location and onset of local grinding burn damage have seemed for a long time to be random and unpredictable, for which reason the feed rates and material removal rates have been increased only incrementally in procedures used in industrial practice. The studies reported in the paper are intended to contribute to the knowledge of the interrelationships between surface zone damage and the effects on flank load-carrying capacity for the case of profile grinding. Grinding tests have been conducted in order to investigate more closely the occurrence of surface properties in the form of grinding burn as a function of grinding parameters. Further studies of the flank load carrying capacity of case hardened gears subjected to different surface properties are intended to provide a more detailed analysis of the interrelationship between gear geometry and different surface properties during the grinding process in a first step.


2008 ◽  
Vol 389-390 ◽  
pp. 362-367 ◽  
Author(s):  
Zbigniew M. Bzymek ◽  
Glenn M. Duzy ◽  
Richard B. Mindek

Truing and dressing are essential processes of grinding wheel preparation. They make the wheel geometry true with respect to its rotational axis and its cutting surface sharp. These factors significantly influence the quality of the final profile and surface produced from the grinding process. Prediction of the optimum wheel surface for grinding, defined as one which produces an accurate profile and cuts most efficiently can greatly minimize the time to optimize grinding wheel performance. This paper describes virtual dressing and truing operations, takes under account vibration of the dressing apparatus and shows how to generate wheel surface replica under different conditions.


2016 ◽  
Vol 874 ◽  
pp. 79-84 ◽  
Author(s):  
Xiang Long Zhu ◽  
Zhen Hua Jiao ◽  
Ren Ke Kang ◽  
Zi Guang Wang ◽  
Hui Xu

Wheel setting is difficult in a grinding process and may directly apply a negative impact on grinding accuracy and efficiency. This study presents a novel method for grinding wheel setting based on acoustic emissions. The method experimentally detects the acoustic emission (AE) signals that come from the touch-down of the grinding wheel with the workpiece. The experimental results show that the measured AE signals monotonically increase with grinding depth and can be used for detection of wheel setting in a grinding process with a detection accuracy better than 0.5μm.


Micromachines ◽  
2019 ◽  
Vol 10 (4) ◽  
pp. 255 ◽  
Author(s):  
Kapłonek ◽  
Nadolny ◽  
Sutowska ◽  
Mia ◽  
Pimenov ◽  
...  

This work demonstrates that molybdenum disulfide can be successfully used as an impregnating substance that is introduced in the abrasive tool structure for improving its cutting properties and favorably affecting the effects of the abrasive process. For the experimental studies, a set of MoS2-treated small-sized grinding wheels with a technical designation 1-35×10×10×109A5X60L10VE0 PI-50 before and after the reciprocating internal cylindrical grinding process of rings made from INCONEL® alloy 718 was prepared. The condition of grinding wheel active surface was analyzed using an advanced observation measurement system based on stylus/optical profilometry, as well as confocal and electron microscopy. The obtained results confirmed the correctness of introduction of the impregnating substance into the grinding wheel structure, and it was possible to obtain an abrasive tool with a given characteristic.


Author(s):  
Peidong Han ◽  
Ioan D. Marinescu ◽  
Anil Srivastava

Single crystal sapphire is of significant interest due to its combination of excellent optical, electrical, and mechanical properties. However, fine grinding of sapphire is quite challenging because of its high hardness and low fracture toughness, making it sensitive to cracking. Wheel loading is a common problem in conventional grinding of hard and brittle materials. ELID grinding shows great promise in achieving a mirror surface finish at a relatively high efficiency. ELID grinding of sapphire was investigated using acoustic emission. The effects of processing parameters on surface finish and acoustic emission signals were evaluated. Correlations were found among the dressing current intensity, surface finish and acoustic emission signals. A smoother surface was obtained using a higher dressing current at the cost of a higher wheel wear rate. The wheel wear mechanism in ELID grinding of sapphire was dominated by bond fracture because the bond strength is reduced by electrolysis. Results indicate that the acoustic emission technique has the potential to be used for monitoring ELID grinding process, detecting the condition of the grinding wheel, and investigating the mechanisms of ELID grinding.


2005 ◽  
Vol 291-292 ◽  
pp. 91-96 ◽  
Author(s):  
Xun Chen ◽  
Q.S. Liu ◽  
Nabil Gindy

Grinding burn is a common phenomenon of thermal damage that has been one of the main constraints in grinding in respect of high efficiency and quality. Use of acoustic emission technique for identifying grinding burn was reported before. However, the AE features of grinding burn are relatively weak and easily merged by other AE sources. This paper presents an investigation of the AE features of the thermal expansion induced by laser irradiation, which was designed to simulate grinding thermal behaviour. By means of the wavelet packet transforms, AE features at the grinding burn temperature can successfully be extracted without other mechanical interferential factors. These clean features can provide a firm foundation for analysing the real grinding burn AE features and for monitoring grinding burn.


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