Type Thermocouple Research Articles

Comparison of temperature rise within pulp chamber during light curing of composite restoration

AbstractIn this study, total of 60 extracted human teeth were divided into four groups. Group I and II were subjected to LCU A (2550 mW/cm2) and Group III and IV to LCU B (700 mW/cm2), respectively. The increase in temperature level from baseline was recorded using K type thermocouple while curing of dentin bonding agent and composite resins. The temperature rise was significantly higher for Light Curing Unit A which had higher intensity light than Light Curing Unit B. Remaining dentin thickness of the prepared tooth also has significant role in the temperature rise. Hence, light curing units should be used with caution to avoid over‐exposure of teeth. Dental practitioners need to prepare teeth with silicone indices and pre‐assessment of radiographs to avoid over‐preparation. Regular check of intensity of light curing unit using commercially available intensity meter is advocated.

Effect of Guiding Sleeve Design on Intraosseous Heat Generation During Implant Site Preparation (In Vitro Study).

To compare the effect of different designs of guiding sleeves on heat generation during implant surgery while using different cooling fluid temperatures. Temperature measurements were performed during guided implant site preparation in bovine rib samples using two K- type thermocouples at 2 mm and 8 mm depths. Three groups were tested according to guiding sleeve design: conventional cylindrical sleeve, open C-shaped sleeve, and modified cylindrical sleeve. Each group was irrigated with three fluid temperatures: 10°C, 15°C, and 20°C. The groups were compared using Kruskal Wallis test followed by post hoc comparisons with Bonferroni correction. The level of statistical significance was set at p = 0.05. Surgical guides with conventional cylindrical sleeve design showed significantly higher heat generation during implant site preparation than guides with both the open C-shaped and the modified cylindrical sleeve designs at both 2mm and 8mm depths. The difference between C-shaped and modified cylindrical sleeves was not significant in any group. Using pre-cooled irrigation fluids (10°C and 15°C) reduced the generated heat; however, the differences within the same group were not statistically significant. The use of a surgical guide with the conventional cylindrical sleeves led to higher heat generation than other sleeve designs, which might reach or near the critical threshold of bone thermal necrosis. Using surgical guides with open sleeves or modified cylindrical sleeves could be helpful in irrigation fluid delivery and decreasing the generated heat.

Base-metal thermocouple tolerances and their utility in real-world measurements

The reference functions and tables for base-metal thermocouples, which relate temperature and electro-motive-force, are specified by thermocouple type, rather than by alloy composition. The common thermocouple types—E, J, K, N, and T—are required to meet the specifications within defined tolerance bands; referred to as either limits-of-error (ASTM, US) or class (IEC, UK and Europe). In this requirement hides a fundamental problem: the tolerances are a manufacturing specification. Despite this, the tolerances are often used as a proxy for expected behaviour. However, these thermocouple types are subject to rapid and irreversible changes after short exposure times to modest temperatures. Thus, tolerance statements are poor predictors of in-use behaviour. This paper initially reviews the development of the base-metal thermocouples before identifying many of the metallurgical processes that lead to departures from the accepted tolerance bands. Focus is specifically given to the processes that occur in several type K and N thermocouples, which exemplify the changes common in the other base-metal thermocouples. From these results, it is shown that the use of traditional calibration techniques can be a futile exercise. Comparisons are then made between as-received thermocouples and those given thermal treatments, that have been designed to allow meaningful calibration while also inhibiting drift. These results show that thermal treatments and calibration are a practicable means to minimise drift over typical periods of use while offering small uncertainties, well within the span of manufacturing tolerances. Lastly it is suggested manufacturers give more information on the testing used to establish conformance with tables and reference functions and that they follow standardised testing procedures.

THE ANALYSIS OF PHOTOVOLTAIC PANEL SYSTEMS

Most of the energy needed today is obtained from fossil fuels. Both the damages that these fuels cause to the environment and the limited resources have led to the search for alternative energy sources. Solar energy is one of the remarkable renewable energy sources, and is considered as one of the solution to meet the power requirement and to protect the environment. Photovoltaic panel systems are one of the substantial renewable energy sources which are rapidly becoming widespread due to its advantage such as converting directly solar energy into electrical energy.
 
 In this study, two different types photovoltaic panels such as monocrystalline and polycrystalline solar panels are examined experimentally and the performance of these panels are assessed. The analysis is carried out for the city of Aydın in Turkey. The experimental measurements are achieved under weather condition of Aydın in August and September months. Besides, the solar radiation is measured using pyranometer device. The panel surface temperature is measured using K type thermocouple. The main purpose of this work is to determine the most suitable panel type for city of Aydın by means of electric power generation and thus to provide scientific data to the investors and companies. The results indicate that for monocrystalline and polycrystalline solar panels, the obtained maximum power are 49.74 W and 46.13 W respectively. In addition, the maximum efficiency of monocrystalline and polycrystalline solar panels is determined to be 13.94% and 12.13%, respectively.

Temperature monitoring of milling processes using a directional-spectral thermal radiation heat transfer formulation and thermography

Temperature is an important property to be monitored during cutting operations, such as in the milling of metals, because it affects the workpiece mechanical properties, the machining tool performance, and the process efficiency. For this reason, authors have used thermography to monitor thermal and spatial gradients, and to estimate temperature. The problem is that IR cameras native applications are mostly based on the diffuse-gray approximation, with emissivity set as a constant value. The diffuse-gray approach is a reasonable choice for opaque surfaces with emissivity approximately constant in respect to the wavelength, which is not the case in most of the time for metals under cutting operation. In this work we propose a more suitable methodology that uses radiative heat transfer directional-spectral relations to estimate cutting process temperatures during face milling of metals, using the full electrical response of commercial infrared cameras as an input. AISI H13 steel was used as the workpiece material. In the first part of the experiments, emissivity was estimated for eight different temperatures from 50 °C to 250 °C, using both directional-spectral and diffuse-gray approaches. Temperature was measured using a thermocouple type T, calibrated using a PT-100 reference from 50 °C to 250 °C. In the second part, we used the emissivity obtained in the first part to estimate the temperature for twelve different cutting conditions, again using both directional-spectral and diffuse-gray approaches. We compared the results of both methods, also with the direct application of emissivity provided in infrared cameras manuals. The temperature deviation between the different approaches were up to 41%, which demonstrates that the temperature estimation procedure affects the results substantially.

Experimental investigation of parabolic dish concentrator with various sizes of receiver

Abstract A satellite dish having an aperture area of 2.626 m2 is modified into a Parabolic dish concentrator (PDC). An anodized aluminium sheet is used as a reflective material. Three different sizes of aluminium made receiver having diameter 0.150 m, 0.228 m, 0.304 m, and thickness 0.001 m with selective coating are placed at the focus of the PDC. The receiver outer temperature is recorded with the help of J type thermocouple. The maximum temperature of 309 °C was achieved in the 0.150 m diameter receiver. The receiver outer temperature depends upon the solar intensity and the wind speed. As the size of the receiver is increases from 0.150 m to 0.304 m, the temperature starts decreasing at the outer surface. The experiment was conducted at NIT, Kurukshetra, India.

Use of web services in technological process control systems

The optimal control of technological objects and processes is usually implemented by computer control systems with complicated structure and relations between elements. On the one hand, it allows to perform the functions of automatic control and regulation, alarms, process status registration and visualization. On the other hand, this leads to a significant complication of the systems because of increased process intensity, speed, accuracy and quality requirements.Use of web services is the most popular approach to solve the problem of integration and coordination of system elements. It is based on the exchange of messages of a special (universal) format between parts of the system and processing the responses.The role of web service and its place in control system has been analyzed. The most appropriate place is between the levels of PLC - controllers and SCADA one. It allows you to receive current information about the state of the technological process and implement the following functions: data acquisition by controllers; storage data to the database; providing data to the operator on demand and it’s visualization in real time; monitoring and alarms of process parameters.The web service build with Microsoft ASP.NET has been proposed for use in computer control systems. The key benefit of this technology are: open-source, cross-platform, fast and scalable. The development of web-services in control systems is a universal approach that can be applied to a large class of objects or processes. In the article the web service for temperature control has been proposed. The key task of the system is temperature data acquisition from the control object, to save information to the database, visualize the temperature curve, notify when the temperature exceeds limits.Since the Microsoft technology stack is already in use, MS SQL has been chosen. To increase the speed of development the Entity Framework Core application has been used, which provides a way to interact with data. To provide the security of the database and prevent development errors, a library has been implemented to access the database. It provides two interfaces Repository and Unit Of Work. Repository is an interface for interacting with each object in the database. The advantage of this interface is abstraction that removes dependency of a specific class implementation.The hardware of control system consists of programmable platform Arduino and such modules: Arduino Uno – the platform on the Atmega 328 microcontroller with built-in interface SPI, I2C, UART, 5 analog inputs and 13 discrete built-in power lines 3.3 and 5 V; MAX6675 - signal conversion module (12-bit ADC); thermocouple type K; ESP8266-01 - module with Wi-Fi interface; DS3132 - real time clock module.The modules interact according to the following algorithm: Arduino calls the thermocouple module and remembers the value, then calls the time module and forms a data period in which it places the time and temperature value. The controller module transmits data to the ESP8266-01 via a programmed UART interface. The Wi-Fi module reads data on the UART bus, forms HTTP request headers and sends JSON text to the server.Thus, web service for SCADA-level has been developed. The control object based on the Arduino hardware platform has been simulated. The developed web service provides the necessary level of security, high indicators of convenience of the human-machine interface, allows to analyze the object and track the past state of the system.

In-depth wood temperature measurement using embedded thin wire thermocouples in cone calorimeter tests

In-depth temperature measurements of wood samples using thermocouples are commonly performed in fire research at all scales. However, the size or the type of thermocouples or how they are placed in the sample can lead to the measured temperature being significantly different. In this work, an original method combining thin wire thermocouples with a meticulous implantation, was used to provide an accurate measurement of the in-depth temperature of wood samples during their degradation. Wood samples were thus equipped with both embedded thin wire thermocouples (0.1 mm diameter) and sheathed thermocouples (1 mm diameter) installed perpendicularly or in parallel to the conductive heat flux to compare the results between the two kinds of measurements. Afterwards, samples were exposed to the cone calorimeter at different heat fluxes (from 16.5 kW.m−2 to 93.5 kW.m−2) in order to measure both in-depth temperature and mass loss during the degradation. The smallness and high flexibility of thin embedded wire thermocouples enabled in-depth temperature measurement without affecting the mass loss measurement. This is usually not possible when using sheathed thermocouples, because of their high stiffness. Results showed that it is crucial to rigorously control the thermocouple implantation, as an underestimation up to was observed for thermocouples put near the surface exposed to the heat flux. There are several reasons for this difference: the heat sink due to conductive heat flux through the thermocouple body, a poor contact between the sensor and the sample and uncertainty about the actual position of the thermocouple. The char front evolution deduced from temperature measurement by wire thermocouples was found to comply with direct measurements of the char layer performed on samples. Finally, the charring rate obtained from in-depth temperature as a function of the heat flux was found to follow an affine law.

Experimental Investigation and Solidification Study of Aluminium alloy Composites

The study on the solidification of aluminium alloys has been reported by the squeeze casting method. In solidification analysis, the formation of casting plays a vital role. To provide quality casting, the preparation of composite is essential. Hence the liquid state processing of the squeeze casting technique is adopted. The application of pressure during the fabrication of composite would change the structure and properties of the developed composite. The squeezing pressure is assigned 30,60,90 and 110MPa, and the melting of the aluminium the selected temperature is 850°C, and the die temperature is 350°C respectively. At 30MPa, the solidification time is recorded at 69 seconds, and the pressure is increased to 110 MPa the solidification is recorded at 33 seconds. The cooling rate is reduced due to increasing squeeze pressure. K type thermocouple has been used to record the temperature values of the aluminium alloy. The theoretical solidification time is calculated, and the results are close to the values which have been taken from the experimental results. Further, the hardness value is identified to measure the grain structure formation in the aluminium alloy, which is correlated with the solidification process.

IR diagnostics of a flame of a new burner when burning liquid hydrocarbons in a steam jet

In the present work, we performed IR diagnostics in the external flame of a new burner using the example of waste engine oil being sprayed by a high-speed jet of superheated steam. The experiments were carried out in a wide range of operating parameters (steam flow rate and temperature and fuel flow rate). In measurements, we used a FLIR thermal imaging camera of the special JADE J530SB series and platinum-rhodium-platinum-rhodium thermocouple of type B. Instantaneous and average temperature fields are obtained. The influence of device operation parameters on the temperature in the external flame of the burner is established. The maximum temperature reaches 1240°C. With increasing mass concentration of steam, a decrease in temperature is observed. This is due to dilution of a combustible mixture and a decrease in its heat capacity. A decrease in the flame temperature in the presence of steam may indicate a decrease in formation of thermal nitrogen oxides.

Transient heat transfer for GPMG’s barrel 7.62x51mm

In this paper, a modified analytical solution for time-dependent one dimension heat diffusion equation in cylindrical coordinate had been mathematically solved to calculate the temperature distribution through thick-walled weapon barrel subjected to successive shots. The analytical solution has been compared with experimental measurements for the temperature at the outer surface of the barrel at two different positions. The General Purpose Machine Gun (GPMG) 7.62X51 mm was considered as the case of study. The results show a good agreement between the analytical model and the experimental work with a difference less than 3 %. The main difference between them mainly as a result of the very short time of the heating phenomena as it takes about 6 (ms) only, although the used Data Acquisition System was able to take a high sampling rate and a high sensitive thermocouple type k with only 0.5 mm thickness had been used.

DECREASING OF THERMOCOUPLE INHOMOGENEITY IMPACT ON TEMPERATURE MEASUREMENT ERROR

The subject of research is accurate temperature measurements by thermocouples whose legs undergone degradation during long term operation at high temperatures. The degradation rate is approximately proportional to the temperature of constant operation of the sections of thermocouple legs and time of operation. Degradation causes two types of errors – due to drift of the conversion characteristic (its gradual change during operation) and due to the acquired thermoelectric inhomogeneity of thermocouple legs (manifests itself as a change in thermocouple conversion characteristic when changing the temperature field even at constant temperatures of the measuring and reference junctions). The aim of the article is to study the method of increasing the accuracy of temperature measurement by thermocouples that have significant thermoelectric inhomogeneity acquired during operation. The aim is achieved by stabilizing the temperature field along the thermocouple legs, so error due to acquired thermoelectric inhomogeneity cannot manifest itself. The tasks of the paper are to estimate the error of temperature measurement using the thermocouple, develop the method for increasing accuracy of temperature measurements by inhomogeneous thermocouples, means of stabilization of the temperature field, methods of control of the temperature field, and experimental study the proposed control methods. There are well-known methods used such as the design of equipment with given parameters and limitations, calculations by solving a system of linear equations, the formation of the necessary functional dependence using a neural network, experimental studies. The obtained results are as follows: stabilization of the temperature field makes it possible to reduce the influence of acquired thermoelectric inhomogeneity of thermocouples, which, according to the literature, can reach 11°С to 1,3°С. It is shown that the developed multi-zone tubular furnace for stabilizing the temperature field due to a close thermal connection between the zones, requires a multi-channel controller that is not prone to self-excitation. There are two methods of control of the temperature field are proposed. One based on the solution of a system of linear equations. The second method is based on the neural network, in which the neural network is trained directly on a multizone furnace. Conclusions. As shown by experimental studies, the proposed methods do not allow the error of the acquired thermoelectric inhomogeneity of thermocouples to manifest itself, which provides an opportunity to increase the accuracy and metrological reliability of temperature measurements by existing types of thermocouples.

Effect of using diode laser on Enterococcus faecalis and its lipoteichoic acid (LTA) in chronic apical periodontitis.

The purpose of this study was to evaluate the effect of diode laser irradiation on Enterococcus faecalis (E. faecalis) and its lipoteichoic acid (LTA). Ninety-six freshly extracted single-rooted teeth were divided into six groups, n = 8 per group. Groups 1, 2, 3, and 4 as laser group (810nm PILOT™ Diode Laser, 400μm fiber diameter, continuous mode, 30s time) with powers at 1.0W, 1.5W, 2.0W, and 2.5W respectively. Group 5 or positive control group (3ml of 1% sodium hypochlorite (NaOCl) irrigation) and group 6 or negative control group (3ml of normal saline (0.9% NaCl) irrigation). Root canal samples were collected before and after receiving laser irradiation and irrigation solution. Cultivable bacteria were determined by counting the colony (CFU/ml). Evaluation of temperature on the external root surface of teeth was done with K type thermocouple using laser at different powers. Enzyme-linked immunosorbant assay (ELISA) was performed to measure the LTA levels and the correlations between E. faecalis count, LTA levels, and rise in temperature were observed using Pearson's correlation test. E. faecalis LTA was subjected to laser irradiation and its structural damage was examined by thin layer chromatography (TLC). Compared with the control groups, all laser groups showed a decreased colony counts and decreased LTA levels with statistically significant difference (p˂0.05). The bactericidal effect and LTA reduction of laser was better at 2.5W power. Laser at 2.5W power had temperature rise of more than 7°C which is beyond the safe thermal threshold level. No statistically significant correlation was found between E. faecalis count, levels of LTA, and rise in external root surface temperature (p˃0.05). TLC results showed a structural damage in the glycolipid moiety of E. faecalis LTA. Diode laser can effectively reduce the E. faecalis count and its LTA levels.

The Impacts of Nanoparticle Concentration and Surfactant Type on Thermal Performance of A Thermosyphon Heat Pipe Working With Bauxite Nanofluid

ABSTRACT Heat pipes are one of the most preferred equipment because they have a variety of superior specifications. In this paper, the improvement of heat transfer properties of a thermosyphon heat pipe that was filled with bauxite nanofluid was experimentally investigated for different nanoparticle concentrations (1%, 2%, and 4%) and surfactant types (Triton X-100 and Sodium Dodecyl Benzene Sulfonate). Bauxite nanoparticles at different concentrations were utilized for the preparation of nanofluid suspensions. Different kinds of surfactants were also doped into the prepared nanofluid suspensions to show off how a surfactant affects the thermophysical properties of the nanofluid. The experiments were done under several heating powers and various mass flow rates of the cooling water circulating on the evaporator section. Temperature distributions both upon the evaporator and the condenser sections were recorded via 8 different K type thermocouples. Cooling water inlet and exit temperatures were also recorded and utilized for theoretical calculations. For doing an experimental comparison, thermal efficiency and resistance of the thermosyphon heat pipe were determined both for distilled water and prepared nanofluid suspensions. Moreover, contact angle-wettability analysis was carried out to determine how nanoparticles affect the surface tension. The encountered problems during the tests were addressed and discussed. The obtained experimental data illustrated that the thermosyphon heat pipe efficiency was increased by up to 20.9% with the usage of a 2% (mass) concentration of bauxite nanofluid and an anionic surfactant. The maximum enhancement in heat pipe’s thermal resistance was found as 24.3%, through bauxite nanofluid usage.

Prolonged intra-operative thermal exposure in endoscopic ear surgery: is it really safe?

The aim of this study was to assess change in temperature, audiometric outcomes and post-operative complications following exposure to different light sources during endoscopic ear surgery. A total of 64 patients diagnosed with chronic otitis media with central perforation and pure conductive hearing loss underwent endoscopic type 1 tympanoplasty. The patients were randomised into two groups based on the light source used: xenon or light-emitting diode. Temperature was measured using a K type thermocouple at the promontory and round window niche. Mean temperature change with respect to operating time, mean audiometric change, incidence of vomiting in the first 24 hours, vertigo and tinnitus at the end of the first week were observed. Mean temperature change showed a statistically significant difference with increasing length of operating time with the xenon light source and when the two light sources were compared for a particular time interval. Mean audiometric change showed statistically significant deterioration at higher frequencies (4, 6 and 8 kHz) with the xenon light source but only at 8 kHz for the light emitting diode source. When the mean audiometric change was compared between light sources for a particular frequency, statistical significance was found at 4, 6 and 8 kHz. Post-operative complications were vomiting, vertigo and tinnitus (p-values of 0.042, 0.099 and 0.147, respectively, between two groups). Light emitting diodes are associated with less significant middle-ear temperature rises and audiometric changes at higher frequencies when compared to xenon light sources. Hence, xenon should be replaced with cooler light sources.

Rancang Bangun Prototype Mesin Pengering Gabah Otomatis Menggunakan Metode PID sebagai Kendali Temperatur

The value of rice grain content after harvest is quite high, around 20-23% in the dry season, and around 24-27% in the wet season. It was drying grain after harvest was processed by the conventional or manual method that carried out the grain drying in the sun. This method has several disadvantages, such as the dependence on the weather, requires a large area, and 54 hours for drying so that the grain becomes dry with a moisture content of 14.12%. From this problem, the researchers made a grain drying machine that could work automatically. The drying machine is made to solve the issues of conventional grain drying so that the machine was completed with a K type thermocouple temperature sensor and grain moisture content. Whereas the heating media uses a fire that is fueled with LPG gas, and then the heat from the fire has flowed into the furnace or grain drying chamber. The heating arrangement was made by regulating of flowing LPG gas to the nozzle through the opened and closed variable valve where the valve shaft was connected to the DC motor shaft. The application of the PID method also used in this drying machine, which has a purpose while controlling the drying temperature to match the Set Value (SV) or the desired temperature at 38oC. The grain moisture content value is considered to have dried up when the grain moisture content value is 14%. The PID method that is implanted into the ATmega16 microcontroller will give a signal to the motor driver circuit to regulate the direction of rotation of the DC motor connected to the opened and closed valve variable. PID method testing was done by trial error and has produced a steady-state error of 5.2% at S0056=38oC with constant values Kp=2, Ki=2, and Kd=10. Whereas for drying grain testing on harvested is done by selecting Ciherang grain with a moisture content of 20% and a weight of 3 kg. The grain drying process takes 30 minutes so that the value of the water content becomes 14% with a drying temperature of 38oC, so the grain drying rate on this machine is 0.17% per minute.

Development of Incubator Analyzer Based on Computer with Temperature And Humidity Parameters

Opening and closing an infant incubator during calibration can cause temperature leaks such as a decrease in the incubator temperature. The purpose of this study is to make the tool "Development Incubator Analyzer appear PC and Non-PC with Temperature and Humidity parameters" with Bluetooth HC05 delivery for Personal Computer display in the form of numbers and temperature graphs. Whereas for non-PCs displayed on a 20x4 LCD with SD Card storage. The contribution of this research is to be able to calibrate baby incubators without a decrease in temperature and monitoring data collection at a maximum distance of 10 meters. To avoid a decrease in temperature, the module is displayed on the Personal Computer and storage on the SD Card. Incubator Analyzer is designed to simplify and facilitate calibration with temperature parameters at 5 points using a DS18B20 sensor, mat temperature using a K type thermocouple and humidity using a DHT22 sensor. In the temperature setting of 34 C and 36 C, the average error result is -4.87% for DS18B20, -7.39% error for mattress temperature, and -24.80% for humidity sensor. Data generated from comparisons using the INCU II test conclude that the measurement results between modules and standard devices have large differences in values. The results of this study can be implemented on baby incubators to increase the appropriateness of the device.

Microfluidic Chip for Trapping Magnetic Nanoparticles and Heating in Terms of Biological Analysis

In this study, we reported the results of the design and the fabrication a planar coil in copper (square, a = 10 mm, 15mm high, 90 turns), these planar coils were integrated in a microfluidic chip for trapping magnetic nanoparticles and local heating applications. A small thermocouple (type K, 1 mm tip size) was put directly on top of the micro-channel in poly(dimethyl-siloxane) in order to measure the temperature inside the channel during applying current. The design of planar coils was based on optimizing the results of the magnetic calculation. The most suitable value of the magnetic field generated by the coil was calculated by ANSYS® software corresponded to the different distances from the coil surface to the micro-channel bottom (magnetic field strength Hmax = 825 A/m). The magnetic filed and heating relationship was balanced in order to manipulating the trapping magnetic nanoparticles and heating process. This design of the microfluidic chip can be used to develop a complex microfluidic chip using magnetic nanoparticles.

Development of an automated system for the determination of thermal conductivity in granular materials

In many devices such as refrigerators, ovens, industrial kitchens, integrated circuits among others, where heat transfer is involved, it is important to know the thermal behavior of the material and the geometric model (cylindrical, spherical, etc.), with which such equipment will be built, to subsequently perform analysis of the parameters evaluated and thus enhance their efficiency. For this reason, it is important to know variables such as thermal conductivity, wall thickness, material, and geometry for new generation equipment. As a result, this work involved the construction of a test bench for the analysis of thermal conductivity in insulating materials, which began with the selection of the components that made up the device, such as resistors, types of thermocouples, specimen geometry, sensors, and finally, the construction of a data acquisition and analysis control system using Arduino and Labview. Subsequently, a device was obtained to measure the temperature in the cylindrical walls with different granular materials. This project was developed in an innovative way, where the thermal behavior of non-pure agglomerated granular materials will generate research in the study area, with the purpose of implementing it in different projects in which heat transfer is involved.

Heat Sink Effect on 6061 Aluminum Alloy Welds with Different Partial Aging Conditions

Partially aged 6061 aluminum plates were welded by the gas metal arc welding process. During the welding process, a cooling system to act as a heat sink was used to extract the heat coming out from the welding process. To determine the experimental weld thermal cycles, K type thermocouples were placed at the heat affected zone. Finite element was used to compute the thermal distribution and isothermal sections generated by welding. The temperature measurements, Vickers microhardness profiles and tensile tests were observed to be related with the microstructural β″ to β′ phase transformation. The over-aging of the heat affected zone tends to diminish when the heat sink is used as compared with the reference welding condition. An increase on tensile strength (about 5.8%) and ductility (close to 29%), for welds performed in partial aging materials with respect to the welds with artificial aging condition (6061-T6 alloy) was also observed.