scholarly journals HEAT ENERGY QUANTITY MEASUREMENT USING ULTRASONIC METHOD

Author(s):  
Anna Pisarets ◽  
S. Polishchuk
2021 ◽  
Vol 5 (3) ◽  
pp. 18-27
Author(s):  
Vladimir Leonid Lanin

Innovative approaches in ultrasonic assistant soldering consist consists of increasing the activity of cavitation and accelerating diffusion processes at the interface between the solder and the soldering material. Besides that, it improves the effectiveness of cavitation processes in melts by saturating gas cavities with diamete rs that are smaller than the resonant sizes of cavitation germs. Gas saturation of liquids and melts raises level of cavitation pressure by 20 25%25%, that intensifies US processing of cleaning, soldering and metallization. Modelling diffusion process showed that the US activation increased the concentration of diffusing elements of Zn and Al in the interface depth by 15 20% on average, and the combined activation by the US and electric field increased it by 30 45%. Furthermore, as the energy quantity adsorbed by melt increases, increased amplitude and frequency of US vibrations induces concentration rise. The heat energy was also boosted by combining the activation of the melt–soldered material system with US vibrations energy and high current pulses. This allows for a faster increase in soldering temperature, as well as improved solder wettability.


2006 ◽  
Vol 137 ◽  
pp. 219-222 ◽  
Author(s):  
W. Marczak ◽  
T. Kowalska ◽  
M. Bucek ◽  
D. Piotrowski ◽  
M. Sajewicz
Keyword(s):  

2020 ◽  
Vol 2020 (1) ◽  
pp. 34-52
Author(s):  
Rafał Szymański

AbstractThe article is in line with the contemporary interests of companies from the aviation industry. It describes thermoplastic material and inspection techniques used in leading aviation companies. The subject matter of non-destructive testing currently used in aircraft inspections of composite structures is approximated and each of the methods used is briefly described. The characteristics of carbon preimpregnates in thermoplastic matrix are also presented, as well as types of thermoplastic materials and examples of their application in surface ship construction. The advantages, disadvantages and limitations for these materials are listed. The focus was put on the explanation of the ultrasonic method, which is the most commonly used method during the inspection of composite structures at the production and exploitation stage. Describing the ultrasonic method, the focus was put on echo pulse technique and the use of modern Phased Array heads. Incompatibilities most frequently occurring and detected in composite materials with thermosetting and thermoplastic matrix were listed and described. A thermoplastic flat composite panel made of carbon pre-impregnate in a high-temperature matrix (over 300°C), which was the subject of the study, was described. The results of non-destructive testing (ultrasonic method) of thermoplastic panel were presented and conclusions were drawn.


Author(s):  
J Downing ◽  
A Hook

Two steel substrate test panels were developed to represent common plate thicknesses found on naval vessels and scanned using the Babcock developed ultrasonic technique. One sample comprised of a series of slotted surface breaking flaws of varying widths and through thicknesses to represent fracturing/cracking. The inspection method detected simulated cracking to a depth of 2mm and 0.5mm in width. The second sample included numerous loss of wall thickness areas of varying diameters and through thicknesses, with the smallest detectable loss of wall thickness being 0.1mm at a 15mm diameter. After proving confidence in detection, there was a need to characterise flaws to provide support and ascertain a repair action. Samples were produced that were subjected to either impact or heat exposure to induce realistic representative damage. The practical ultrasonic method was successfully used to independently characterise between the samples, with induced de-laminations caused by blisters, and multi layered matrix cracking caused by varying levels of projectile impacts, due to their unique morphology.


Author(s):  
Shirley García ◽  
Thairon Reis ◽  
Auteliano Antunes dos Santos Junior

2020 ◽  
Vol 2020 (4) ◽  
pp. 60-67
Author(s):  
Boris Pruss ◽  
Viktor Romanov ◽  
Yaroslav Prozorov ◽  
Olga Pleskacheva

The paper presents the theory of calculating heat loss through the fences of timber drying chambers. The software for computer modeling of the process of transferring heat energy through the fences of the drying chamber, consisting of various heat-insulating materials, for calculating heat losses during drying of sawn timber is described. The efficiency of the use of modern heat-insulating materials to reduce heat losses during drying of sawn timber has been experimentally confirmed.


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