scholarly journals Examining the Possibilities of Analyzing the Solidification Process of Al-Si Alloy with the Infrared Camera

2016 ◽  
Vol 16 (1) ◽  
pp. 89-94 ◽  
Author(s):  
R. Władysiak ◽  
A. Kozuń ◽  
T. Pacyniak

Abstract The paper presents the results of the crystallization process of silumin by the TDA thermographic method and the results of the cast microstructure obtained in the sampler ATD-10, that was cooling down in ambient air. The study was conducted for silumins AlSi8 and AlSi11 unmodified. The work demonstrated that the use of thermal imaging camera allows for the measurement and recording the solidification process of silumin. Thermal curve was registered with the infrared camera and derivative curve that was calculated on the base of thermal curve have both a very similar shape to adequate them TDA curves obtained from measurements using a thermocouple. Test results by TDA thermographic method enable quantitative analysis of the kinetics of the cooling and solidification process of hypo-and neareutectic silumins.

2015 ◽  
Vol 15 (3) ◽  
pp. 81-84
Author(s):  
R. Władysiak ◽  
A. Kozuń

Abstract The paper presents the results of the crystallization process of silumin by the TDA thermographic method and the results of the cast microstructure obtained in the sampler TDA-10, that was cooling down in ambient air. The study was conducted for silumin AlSi11 unmodified. The work demonstrated that the use of thermal imaging camera allows for the measurement and recording the solidification process of silumin. Thermal curve was registered with the infrared camera and derivative curve that was calculated on the base of thermal curve have both a very similar shape to adequate them TDA curves obtained from measurements using a thermocouple. Test results by TDA thermographic method enable quantitative analysis of the kinetics of the cooling and solidification process of neareutectic silumin.


2017 ◽  
Vol 17 (2) ◽  
pp. 137-144 ◽  
Author(s):  
R. Władysiak ◽  
A. Kozuń ◽  
K. Dębowska ◽  
T. Pacyniak

Abstract The work is a continuation of research concerning the influence of intensive cooling of permanent mold in order to increase the casting efficiency of aluminium alloys using the multipoint water mist cooling system. The paper presents results of investigation of crystallization process and microstructure of multicomponent synthetic hypereutectic alloy AlSi20CuNiCoMg. The study was conducted for unmodified silumin on the research station allowing the cooling of the special permanent sampler using a program of computer control. Furthermore, the study used a thermal imaging camera to analyze the solidification process of multicomponent alloy. The study demonstrated that the use of mold cooled with water mist stream allows in wide range to form the microstructure of hypereutectic multicomponent silumin. It leads to higher homogeneity of microstructure and refinement of crystallizing phases of casting.


2021 ◽  
Vol 25 (3) ◽  
pp. 65-72
Author(s):  
Krzysztof Sawicki ◽  
Grzegorz Bieszczad ◽  
Tomasz Sosnowski ◽  
Mariusz Mścichowski

The article presents a new concept of using thermography – steganography in thermography. Steganography is a technique of hiding information in a non-obvious way and belongs to the field of science related to information security. This article examines three examples of steganographic channels – covert communication channels that use thermal imaging devices in three different ways. The first proposed method uses the possibility of alternating the scene observed by the infrared camera in a way that additional information is included in the thermogram. The second method, called ThermoSteg, uses modification of one of the parameters of the thermal imaging camera (integration time) to embed the signal containing hidden information. The third method is based on digital thermograms and the methods of replacing dead pixels in them by creating the so-called zombie pixels carrying secretive information. Three methods have been implemented under real conditions and proven to work in practice.


2013 ◽  
Vol 2013 (1) ◽  
pp. 000964-000969
Author(s):  
Bennion Cannon ◽  
Frank Friedl ◽  
Gary Gisler

This paper details the thermal evaluation of high-current polyimide rigid and rigid-flex printed wiring boards in a vacuum. Although industry standards, such as IPC-2152 or MIL-STD-275, can be used to determine required trace width for PWB traces that carry current to between 20 or 30 amps for multiple copper plane thicknesses, they typically cannot be used to determine trace width for PWB traces that handle current greater than 15 amps. This paper presents results from testing and analysis of high-current rigid and rigid-flex PWBS that must carry current of up to 60 amps. Testing was performed in vacuum on a controlled-temperature platen, measuring board temperature at specific locations to determine performance of different trace widths using 2 and 4 ounce copper layers. A thermal imaging camera was used to identify PWB hot spots. Test results were compared to IPC-2152 standards, extrapolated to 60 amps current.


Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1156
Author(s):  
Dejia Chen ◽  
Lisha Lei ◽  
Meishuai Zou ◽  
Xiaodong Li

The non-isothermal crystallization kinetics of double-crystallizable poly(ethylene glycol)–poly(l-lactide) diblock copolymer (PEG-PLLA) and poly(ethylene glycol) homopolymer (PEG) were studied using the fast cooling rate provided by a Fast-Scan Chip-Calorimeter (FSC). The experimental data were analyzed by the Ozawa method and the Kissinger equation. Additionally, the total crystallization rate was represented by crystallization half time t1/2. The Ozawa method is a perfect success because secondary crystallization is inhibited by using fast cooling rate. The first crystallized PLLA block provides nucleation sites for the crystallization of PEG block and thus promotes the crystallization of the PEG block, which can be regarded as heterogeneous nucleation to a certain extent, while the method of the PEG block and PLLA block crystallized together corresponds to a one-dimensional growth, which reflects that there is a certain separation between the crystallization regions of the PLLA block and PEG block. Although crystallization of the PLLA block provides heterogeneous nucleation conditions for PEG block to a certain extent, it does not shorten the time of the whole crystallization process because of the complexity of the whole crystallization process including nucleation and growth.


2021 ◽  
pp. 112067212110237
Author(s):  
Ari Leshno ◽  
Ori Stern ◽  
Yaniv Barkana ◽  
Noa Kapelushnik ◽  
Reut Singer ◽  
...  

Purpose: Accumulating evidence suggests that neuroinflammation and immune response are part of the sequence of pathological events leading to optic nerve damage in glaucoma. Changes in tissue temperature due to inflammation can be measured by thermographic imaging. We investigated the ocular surface temperature (OST) profile of glaucomatous eyes to better understand the pathophysiology of these conditions. Methods: Subjects diagnosed with glaucoma (primary open angle glaucoma [POAG] or pseudo exfoliation glaucoma [PXFG]) treated at the Sam Rothberg Glaucoma Center (11/2019–11/2020.) were recruited. Healthy subjects with no ocular disease served as controls. The Therm-App thermal imaging camera was used for OST acquisition. Room and body temperatures were recorded, and the mean temperatures of the medial cantus, lateral cantus, and cornea were calculated with image processing software. Results: Thermographic images were obtained from 52 subjects (52 eyes: 25 POAG and 27 PXFG) and 66 controls (66 eyes). Eyes with glaucoma had a significantly higher OST compared to controls (mean 0.9 ± 0.3°C, p < 0.005). The difference between the two groups remained significant after adjustment for age, sex, intraocular pressure (IOP) and room and body temperatures. Lens status and topical IOP-lowering medication did not significantly affect OST. A subgroup analysis revealed that the OST was higher among eyes with POAG compared to eyes with PXFG, but not significantly. Conclusions: Differences in the OST between glaucomatous and normal eyes strengthens current thinking that inflammation affects the pathophysiology of glaucoma. Longitudinal studies are warranted to establish the prognostic value of thermographic evaluations in these patients.


Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3258
Author(s):  
Dawid Szurgacz ◽  
Sergey Zhironkin ◽  
Stefan Vöth ◽  
Jiří Pokorný ◽  
A.J.S. (Sam) Spearing ◽  
...  

The paper discusses the results of a study carried out to determine the thermal condition of a conveyor power unit using a thermal imaging camera. The tests covered conveyors in the main haulage system carrying coal from a longwall. The measurements were taken with a thermal imaging diagnostic method which measures infrared radiation emitted by an object. This technology provides a means of assessing the imminence and severity of a possible failure or damage. The method is a non-contact measuring technique and offers great advantages in an underground mine. The thermograms were analysed by comparing the temperature distribution. An analysis of the operating time of the conveyors was also carried out and the causes of the thermal condition were determined. The main purpose of the research was to detect changes in thermal state during the operation of a belt conveyor that could indicate failure and permit early maintenance and eliminate the chance of a fire. The article also discusses the construction and principle of operation of a thermal imaging camera. The findings obtained from the research analysis on determining the thermal condition of the conveyor drive unit are a valuable source of information for the mine’s maintenance service.


Author(s):  
Avadhesh Kumar Sharma ◽  
Mayank Modak ◽  
Santosh K. Sahu

Impinging jets are commonly utilized in the run-out table (ROT) cooling in the hot rolling process in steel manufacturing industries. The phenomenon of rapid cooling of a sufficiently hot surface is termed as the quenching. The present paper reports the rewetting behavior of 0.15 mm thick hot moving stainless steel foil (SS-304) by circular impinging jet from bottom side through experimental investigation. The transient temperature of the hot foil is recorded by using thermal imaging camera (A655sc, FLIR system). Tests are performed for a varied range of Reynolds number (Re = 2500–10000), nozzle to plate distance (z/d = 6), moving plate velocity (0–40 mm/s) and initial surface temperature 500±10 °C. Transient temperature obtained from thermal imaging camera is used to evaluate rewetting time and rewetting velocity. Based on the experimental investigation correlation has been proposed to predict non-dimensional rewetting velocity as a function of various parameters, namely, Reynolds number, non-dimensional axial distance and moving plate velocity.


Author(s):  
M. Fatih Toy ◽  
Onur Ferhanoglu ◽  
Hamdi Torun ◽  
F. Levent Degertekin ◽  
Hakan Urey

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