scholarly journals A Review of the Radio Frequency Non-destructive Testing for Carbon-fibre Composites

2016 ◽  
Vol 16 (2) ◽  
pp. 68-76 ◽  
Author(s):  
Zhen Li ◽  
Zhaozong Meng

AbstractThe purpose of this paper is to review recent research on the applications of existing non-destructive testing (NDT) techniques, especially radio frequency (RF) NDT, for carbon-fibre reinforced plastics (CFRP) composites. Electromagnetic properties of CFRP composites that are associated with RF NDT are discussed first. The anisotropic characteristic of the conductivity and the relationship between the penetration depth and conductivity should be paid much attention. Then, the well-established RF NDT including eddy current technique, microwave technique and RF-based thermography are well categorised into four types (i.e. electromagnetic induction, resonance, RF-based thermography and RF wave propagation) and demonstrated in detail. The example of impact damage detection using the induction and resonance methods is given. Some discussions on the development (like industrial-scale automated scanning, three-dimensional imaging, short-range ultra-wideband (UWB) imaging and the radio frequency identification technology (RFID)-based NDT) are presented.

Relevance of the problem of the development of technical means (GPR) and algorithms for processing ultra-wideband signals follows from the wide range of possibilities that these means of non-destructive testing and remote sensing provides, together with the potential of modern computing tools and software. Of particular interest in this regard are the results obtained by using various effects associated with a change in the polarization state of both primary (probing) pulses and signals reflected from complex multilayer media to detect defects in them. This is due to the possibility of not only quickly detecting heterogeneities, but also with the relatively low cost of such work. The purpose of the work is a review of various technical means (pulsed georadars) and signal processing methods for detecting various internal inhomogeneities in plane-layered media. These heterogeneities include, in addition to various internal communications elements (cables) and technical elements (drainage pipes), also dangerous externally invisible defects - subsurface cracks and delamination (interruption of contact between the layers). Materials and methods. The paper provides an overview of methods developed by the author, among others, which are designed to solve primarily the practical problems of detecting subsurface inhomogeneities and defects in plane-layered media. The physical basis for the creation of these methods was the result of many years of research by the author related to the analysis of the polarization state of complex (including pulsed) signals scattered by various objects. Results. The basis of the considered results is made up of both scientific articles and patents of Ukraine for inventions and utility models obtained by the author. Conclusions. The review of the results and various methods presented in the article is another confirmation of the wide possibilities offered by new means of remote sensing and non-destructive testing. These tools include not only the devices themselves (elements for obtaining primary data), but also information processing algorithms and software, combined into a single methodology for collecting, processing and subsequent storage of data on the current state of the examined technical and natural objects.


2021 ◽  
Vol 23 (1) ◽  
pp. 33-44
Author(s):  
Evgeny Artamonov ◽  
◽  
Andrey Tveryakov ◽  
Anton Shtin ◽  
◽  
...  

Introduction. Today, under the conditions of sanctions, the Russian Federation, more than ever before, needs the development of energy-saving technologies in various industries. There is no secret that when assigning cutting modes for new materials, tool companies conduct tests for the destruction of replaceable cutting inserts during cutting, the obtained numerical values are published in catalogs. The greatest impact on the life and operability of hard alloy cutting tools is exerted by the physical and mechanical properties of tool materials. Studies have shown that the physical and mechanical properties of tungsten hard alloys in the process of operation, namely in the process of cutting difficult-to-process materials under the influence of high temperatures, vary symmetrically. During the development of the laboratory plant, a literary review was carried out, which showed that at the moment non-destructive testing methods of technological facilities are widely used. Methods of non-destructive testing of technological objects allow conducting studies of the state of material, defects in the structure, internal changes, without samples destroying; this advantage was decisive during the literary review. The object of this study is replaceable cutting hard alloy inserts made of single carbide hard alloy В35 (92%WC+8%Co), tetrahedral in the state of supply. The subject of the study is the relationship between the changes of the magnetic component of the properties of a single-carbide hard alloy В35 (92%WC+8%Co) depending on the effect of high temperatures on it. This study is based on the laws of physics of the division of electrodynamics, as well as well-known non-destructive testing techniques, scientific foundations of material science. All studies are carried out in accredited laboratories of Tyumen Industrial University. The reliability of the obtained data is confirmed by the high correlation of the results of numerical values with the data obtained by the scientific predecessors. Research methodology. The paper shows the developed plant for determination of the maximum operability temperature of replaceable cutting hard-alloy inserts on the basis of study of change of electromagnetic properties. The method of research is given. Tests of the specimen are carried out during heating of replaceable cutting inserts made of tungsten hard alloy B35 (92%WC+8%Co). The heating temperature interval is selected in accordance with the temperature mode of the cutting process in the blade treatment of hard-to-process materials. Thus, heating is carried out in the range from 0 to 1000˚ C. The heating itself is carried out by the flame method manually. Results and discussions. Based on the results of experimental studies, tables of the results are compiled, where, with an interval of 10 °C, the corresponding values of the magnetic field of eddy currents induced in replaceable cutting inserts made of tungsten hard alloy B35 (92 %WC+8 %Co) are indicated. The results of the investigation are obtained to determine the maximum operability temperature of replaceable cutting hard alloy inserts based on the study of the change in electromagnetic properties for the hard alloy B35 (92%WC+8%Co) amounted to 460…730 °C, which corresponds to a cutting speed of 18 m/min during the treatment of the alloy EI867-VD (57 %Ni9 %Mo10 %Cr6 %W4.2 %Al4 %Co). On the basis of persistent tests in factory conditions, it is proved that the developed technique allows determining temperature intervals of maximum operability based on the study of changes in electromagnetic properties (magnetic field of eddy currents arising in replaceable cutting inserts) of hard alloys. These intervals make it possible to assign the most appropriate operating conditions for the cutting tool based on a scientifically sound technique that allows using the maximum tool resource.


Sign in / Sign up

Export Citation Format

Share Document