ACOUSTIC EMISSION UNDER TEMPERATURE TESTS OF MATERIALS

Vitalii Babak,Viktor Kalita,Sergay Filonenko

doi:10.3846/16487788.2005.9635914

Vitalii Babak, Viktor Kalita + Show 1 more

Open Access

https://doi.org/10.3846/16487788.2005.9635914

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Journal: Aviation	Publication Date: Dec 31, 2005
Citations: 7	License type: cc-by

Affiliation: National Aviation University

Abstract

The theoretical research of the influence of temperature on the parameters of the alteration of acoustic emission signals from plastic deformation is considered. It is shown that increasing temperatures cause an increase in the amplitude of acoustic emission signals in an area of low temperatures and a decrease in an area of high temperatures. At the same time, there is an intermediate area of temperatures in which the amplitude of acoustic emission signals remains constant when temperature is increased. As shown in the article, this fact is connected with the alteration of the process of plastic deformation.

Highlights

In industry there is a significant amount of equipment that operates work in conditions of mechanical, and temperature deformations
As is known, is caused by the movement of dislocations that move, make multiple copies, and stop during material deformation [3, 2, 1]. The process of their movement is accompanied by AE signals that appear because they overcome the barriers by movable dislocations, which was considered in the model of AE signal from plastic deformation [4, 5]
UD l0 d D ; ao peak value of a single displacement pulse is generated by a movable dislocation (Fig.1); d D - average duration of an indignation pulse; l o - a distance between two generation acts; u D - a velocity of dislocation movement, which is considered as a constant; M, B - the constants dependent on physicomechanical characteristics of material; a - velocity of material loading

Summary

Introduction

In industry there is a significant amount of equipment that operates work in conditions of mechanical, and temperature deformations. Temperature will influence the character of the development of the given processes and should lead to the alteration of the parameters of the AE of signals, both at formation of a crack, and during plastic deformation. According to the results received in the work [4], the parameters of the AE signal from plastic deformation are defined, both by number of movable dislocations, and by conditions of their movement, i.e. factors which depend directly on temperature.

Results

Conclusion