My Research Work
My name is Ivan Ivanov. I am a first-year post-graduate student of National Technical University “Kharkov Polytechnic Institute”. I am a graduate of the same university. Now I work at the chair of “Devices and methods of nondestructive testing” as an assistant. My scientific adviser is Pyotr Petrovich Petrov, professor of the chair of “Devices and methods of nondestructive testing”.
The subject of my research work is enhancement of the ultrasonic testing method by capacitor transducers.
Ultrasonic fluctuations and waves are widely applied in practice. Under the influence of powerful ultrasonic fluctuations many technological processes, such as plastic welding, surface cleaning, coagulation of suspended particles, cutting of fragile materials, etc, are successfully implemented. Ultrasonic waves find wide application as a means of measurement, testing and diagnostics, for example in hydrolocation and medical research.
Industrial application of new constructional materials and technological production processes brings about the development of new and the improvement of the existing methods of quality monitoring of materials without their destruction.
The acoustic method of nondestructive testing has lately found the widest application in industry. It is being intensively developed and is considered one of the most universal quality monitoring techniques.
Now ultrasound is used to test metal ware, rubber, plastic, concrete, composite and compound materials, products having an intricate surface form, welds and many other objects. The acoustic method makes it possible to detect not only macroscopic defects in metals, but also to determine their structure, phase condition, grain homogeneity, inter-crystalline corrosion, etc. Automation of the acoustic testing has increased its productivity and led to "know-how" improvement of its quality. The acoustic method covers more than 60% of all non-destructive testing procedures.
Wide experience of practical application of this method has revealed the spheres where it is not effective. Poor results are obtained while testing products with dirty surfaces, objects damaged by corrosion, coated with paints, polymeric films and other insulators, in defectoscopy of hot and cold products, high-speed testing, etc. To fill the existing niche, the devices which do not require any contact liquid for their operation may be applied. The most perspective among such devices can be the ones created on the basis of a condenser technique (CT) of excitation and reception of ultrasonic fluctuations. The use of CT can cover various spheres of nondestructive testing.
CT provides broad information on the properties of the material under investigation. It can also be applied to create devices evaluating geometrical sizes of products, the thickness of walls and separate layers of multilayer products, the diameter and heterogeneity of products with a curvilinear surface, etc. Application of the other techniques for this purpose, e.g. ultrasonic one, is accompanied by the occurrence of an additional measurement error caused by attenuation of ultrasonic fluctuations in the material, signal dispersion on the rough surfaces of section borders of tested layers and by the change of the speed and length of ultrasonic fluctuations wave which have resulted from the change of material properties.
Therefore, the goal of my research is to analyze the experience of the ultrasonic testing application and develop scientific and technological bases for the creation of highly effective devices for CT defectoscopy, thickness measurement and study of physical and mechanical properties of materials.