scholarly journals Evaluation of Adhesion Properties of Hard Coatings by Means of Indentation and Acoustic Emission

Coatings ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 919
Author(s):  
Peter Drobný ◽  
David Mercier ◽  
Václav Koula ◽  
Sára Ivana Škrobáková ◽  
Ľubomír Čaplovič ◽  
...  
Keyword(s):  
Acoustic Emission ◽  
Acoustic Emissions ◽  
Hard Coatings ◽  
Evaluation Methodology ◽  
Wear Properties ◽  
Adhesion Properties ◽  
Measuring Device ◽  
Emission Signal ◽  
Static Indentation ◽  
Instrumental Indentation

In general, the mechanical properties of hard thin coatings are investigated using indentation methods. Material characteristics of hard coatings, such as elastic modulus and hardness, are evaluated by means of nanoindentation and an appropriate evaluation methodology. The most popular method used to obtain the coating properties required using nanoindentation is the evaluation based on the Oliver and Pharr methodology. Adhesion and wear properties can be calculated using these data. In this study, we used a novel method to evaluate the wear and adhesion of coatings. A special measuring device combined with static indentation and acoustic emission signal detection was developed to evaluate the adhesion of coatings. The device consists of a macrohardness instrumental indentation device equipped with an acoustic emission measuring gauge. It was used to investigate crack formation and adhesion of coatings deposited on different substrates using acoustic emissions data. The results using both the existing and novel methods were compared and evaluated.

Mechanical and Adhesive Properties of Plasma CVD Coatings on Various Substrates Using Scratch Test

2006 ◽  
Vol 116-117 ◽  
pp. 304-307 ◽  
Author(s):  
Dae Cheol Ko ◽  
Jung Min Lee ◽  
Byung Min Kim
Keyword(s):  
Acoustic Emission ◽  
Acoustic Emission Signal ◽  
Normal Force ◽  
Chemical Vapor ◽  
Scratch Test ◽  
Hard Coatings ◽  
Plasma Cvd ◽  
Plasma Chemical ◽  
Adhesive Properties ◽  
Emission Signal

In this paper, the adhesive properties of hard coatings(TiN, TiCN) made by plasma chemical vapor depositions on non-nitrided and nitrided substrates was estimated using the scratch test, where adhesion was measured by the critical load (Lc). This value was determined as the normal force affecting the indenter and causing the coating detachment as well as the acoustic emission signal containing the information on the extent of coating damage. Results of the test showed that harder substrates and coatings give higher values of critical loads.

Research of the cold resistance of metals by indentation with registration of an acoustic emission signal

2020 ◽  
pp. 61-64
Author(s):  
Yu.G. Kabaldin ◽  
A.A. Khlybov ◽  
M.S. Anosov ◽  
D.A. Shatagin
Keyword(s):  
Neural Network ◽  
Artificial Neural Network ◽  
Acoustic Emission ◽  
Acoustic Emission Signal ◽  
Low Temperatures ◽  
Cold Resistance ◽  
Emission Signal ◽  
Impact Bending ◽  
Artificial Neural

The study of metals in impact bending and indentation is considered. A bench is developed for assessing the character of failure on the example of 45 steel at low temperatures using the classification of acoustic emission signal pulses and a trained artificial neural network. The results of fractographic studies of samples on impact bending correlate well with the results of pulse recognition in the acoustic emission signal. Keywords acoustic emission, classification, artificial neural network, low temperature, character of failure, hardness. [email protected]

scholarly journals Prediction of shallow bit position based on vibration signal monitoring of bit broken rock

2021 ◽  
Vol 17 (1) ◽  
pp. 155014772199170
Author(s):  
Jinping Yu ◽  
Deyong Zou
Keyword(s):  
Acoustic Emission ◽  
Time Domain ◽  
Vibration Signal ◽  
Rock Breaking ◽  
Drill String ◽  
Mean Square ◽  
Drilling Force ◽  
Emission Signal ◽  
Force Signal ◽  
The Mean

The speed of drilling has a great relationship with the rock breaking efficiency of the bit. Based on the above background, the purpose of this article is to predict the position of shallow bit based on the vibration signal monitoring of bit broken rock. In this article, first, the mechanical research of drill string is carried out; the basic changes of the main mechanical parameters such as the axial force, torque, and bending moment of drill string are clarified; and the dynamic equilibrium equation theory of drill string system is analyzed. According to the similarity criterion, the corresponding relationship between drilling process parameters and laboratory test conditions is determined. Then, the position monitoring test system of the vibration bit is established. The acoustic emission signal and the drilling force signal of the different positions of the bit in the process of vibration rock breaking are collected synchronously by the acoustic emission sensor and the piezoelectric force sensor. Then, the denoised acoustic emission signal and drilling force signal are analyzed and processed. The mean value, variance, and mean square value of the signal are calculated in the time domain. The power spectrum of the signal is analyzed in the frequency domain. The signal is decomposed by wavelet in the time and frequency domains, and the wavelet energy coefficients of each frequency band are extracted. Through the wavelet energy coefficient calculated by the model, combined with the mean, variance, and mean square error of time-domain signal, the position of shallow buried bit can be analyzed and predicted. Finally, by fitting the results of indoor experiment and simulation experiment, it can be seen that the stress–strain curve of rock failure is basically the same, and the error is about 3.5%, which verifies the accuracy of the model.

Three-Point Bending Test Evaluation of Concrete Specimens by Non-Traditional Analysis of Acoustic Emission Method

2016 ◽  
Vol 837 ◽  
pp. 198-202
Author(s):  
Luboš Pazdera ◽  
Libor Topolář ◽  
Tomáš Vymazal ◽  
Petr Daněk ◽  
Jaroslav Smutny
Keyword(s):  
Acoustic Emission ◽  
Signal Analysis ◽  
Measurement Data ◽  
Bending Test ◽  
Test Evaluation ◽  
Acoustic Emission Method ◽  
Emission Method ◽  
Three Point Bending ◽  
Time Frequency ◽  
Emission Signal

The aim of the paper is focused on the analysis of the mechanical properties of the concrete specimens with plasticizer at three point bending test by the signal analysis of the acoustic emission signal. The evaluations were compared the measurement and the results obtained with theoretical presumptions. The Joint Time Frequency Analysis applied on measurement data and its evaluation is described. It is well known that the Acoustic Emission Method is a very sensitive method to determine active cracks into structure. However, evaluation of acoustic emission signals is very difficult. A non-traditional method was used to signal analysis of burst acoustic emission signals recorded during three point bending test.

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