Application of Infrared Thermography to determine Stored Energy of Deformation in Aluminide Coated near-α Titanium Alloy during Tensile Deformation (original) (raw)
Related papers
Materials Science and Engineering: A, 2013
Determination of strain for initiation of rapid crack growth is vital for designing coated components for aerospace applications. Knowledge of such strain is useful for prevention of catastrophic failure of coated components. In the present study this critical strain has been determined during tensile deformation of aluminide coated near-α titanium alloy using infrared thermography. A single step on-line method of determination of stored energy change as a function of true plastic strain, that incorporates conduction heat loss correction in a simple way, has been used to determine such strain level. It is shown that beyond a strain level the crack ensemble that form becomes unstable and further straining leads to rapid crack growth in the coating that penetrates into the substrate material. This manifests in an unprecedented trend in the stored energy change that has been identified with the strain for inception of rapid crack growth.
Thermographic studies on IMI-834 titanium alloy during tensile loading
Materials Science and Engineering: A, 2008
To study the material deformation kinetics under monotonic loading conditions, infrared radiation thermography (IRT) has been used in the present investigation. Studies were performed on IMI-834 titanium alloy, which is used in the compressor module of an aeroengine. The compressor has variable states of stress triaxialities at different locations. The effect of stress triaxiality on material deformation was investigated with the use of smooth and axisymmetrically notched round tensile specimens of the alloy. Instantaneous surface temperatures were measured on specimens during tensile deformation through IRT technique. The notched specimen exhibited localized and higher rate of temperature evolution during loading. Using surface temperature evolution curves, thermoelastic and inelastic regions were identified for smooth and notched specimens. With the help of Lord Kelvin's equation, stresses were predicted for thermoelastic region. A good correlation was found between the predicted and experimental stresses for this region.
A study of the stored energy in titanium under deformation and failure using infrared data
The work is devoted to the experimental study of heat dissipation caused by plastic deformation and failure processes taking place in a titanium alloy Ti-4.2Al-1.6Mn. To investigate the time evolution and spatial distribution of temperature, a set on experiments has been carried out on plate titanium smooth specimens and specimens with pre-grown centered fatigue cracks. The original mathematical algorithm for experimental data processing has been applied to obtain the power of heat dissipation generated by plastic deformation and stored energy rate. It is shown that the stored energy is accumulated in titanium specimens undergoing fatigue tests, and the stored energy rate is equal to zero at the time of damage to fracture transition.
The application of the infrared thermography on titanium alloy for studying fat.PDF
The infrared thermography is an attractive tool for studying the fatigue behavior of materials. Based on two theoretical models of fatigue damage indicators, this work studied the fatigue properties of the virgin Ti-6Al-4V alloy. According to the two damage indicators and the energy theory, the relationship between the macro-phenomenon and the micro-structural evolution during fatigue process was discussed. The fatigue limit of the titanium alloy was rapidly determined based on the measured temperature increment signals. The capability of the infrared thermographic method on the evaluation of fatigue properties was validated.
Thermoelastic stress analysis of titanium components and simultaneous assessment of residual stress
EPJ Web of Conferences, 2010
The thermoelastic effect describes a linear relationship between change in body temperature and state of stress in the presence of adiabatic conditions. This approach considers the material properties constant with temperature, which is not correct for all materials. Experimental results and a review of the theory, especially for the titanium and some alloys of aluminium, have shown that the thermoelastic signal is also dependent of mean stress of the material. The use of titanium in various fields of application makes interesting use of thermoelastic technique as full field stress analysis technique. However, it is necessary to make a correction of the measure in relation to the mean stress. The possibility to measure the mean stress allows also an evaluation of residual stresses on the surface of titanium components.
Proceedings of the 2016 International Conference on Quantitative InfraRed Thermography, 2016
Results of initial investigation of thermomechanical couplings in innovative β-Ti alloy called Gum Metal subjected to tension are presented. The experimental setup , consisting of testing machine and infrared camera, enabled to obtain stress-strain curves with high accuracy and correlate them to estimated temperature changes of the specimen during the deformation process. Both ultra-low elastic modulus and high strength of Gum Metal were confirmed. The infrared measurements determined average and maximal temperature changes accompanying the alloy deformation process, allowed to estimate thermoelastic effect, which is related to the alloy yield point. The temperature distributions on the specimen surface served to analyze strain localization effects leading to the necking and rupture. 1. Motivation Gum Metal, a new class of β-type multifunctional titanium alloys, has attracted considerable attention in the past decade due to its outstanding mechanical properties. The underlying mechanisms of its excellent performance are still unclear. The literature reports have not covered thermographic analysis of the alloy so far. Since infrared techniques and studies of thermomechanical couplings are a great tool for better understanding of mechanical behavior and phenomena occurring in materials the present research aimed at conducting thermomechanical and thermographic investigation of Gum Metal during tension.
Multiphysics Study of Tensile Testing using Infrared thermography
The International Journal of Multiphysics, 2019
In this work, the IR thermography was used to study the steel specimens (DIN 50125 Standard) undergoing the tensile tests. The tensile tests were performed using GUNT® Hamburg Universal Material Tester. The tensile specimens were clamped, and the test force was generated using a handoperated hydraulic system. A dial gauge measured the elongation of the specimens. Using the WP 300.20 system for data acquisition, the measured values for force and displacement were recorded in a PC. The IR thermographic imaging was performed using the FLIR® T1030sc IR camera and ResearchIR Max software. The steel specimens were coated with high emissivity paint. Thermography revealed that the steel specimens show noticeable thermal signature when undergoing tensile loading. The samples were found to be warmer by 20-25 °C at the time of failure. The tests were repeated under various surrounding temperatures such as 25 °C,-5 °C,-10 °C,-15 °C, and-20 °C. The same study was compared with the finite element numerical simulation in ANSYS® Workbench. The experimental and simulation results were found to be in a qualitative agreement.
Study of Tensile Testing using Infrared thermography
In this work, the IR thermography was used to study the steel specimens (DIN 50125 Standard) undergoing the tensile tests. The tensile tests were performed using GUNT® Hamburg Universal Material Tester. The tensile specimens were clamped, and the test force was generated using a handoperated hydraulic system. A dial gauge measured the elongation of the specimens. Using the WP 300.20 system for data acquisition, the measured values for force and displacement were recorded in a PC. The IR thermographic imaging was performed using the FLIR® T1030sc IR camera and ResearchIR Max software. The steel specimens were coated with high emissivity paint. Thermography revealed that the steel specimens show noticeable thermal signature when undergoing tensile loading. The samples were found to be warmer by 20-25 °C at the time of failure. The tests were repeated under various surrounding temperatures such as 25 °C, -5 °C, -10 °C, -15 °C, and -20 °C. The same study was compared with the finite ele...
Infrared imaging and thermomechanical behaviour of solid materials
Proceedings of the 2000 International Conference on Quantitative InfraRed Thermography, 2000
Infrared thermography gives valuable information useful to observe, understand and model the thermomechanical behaviour of solids. The theoretical framework of standard materials is used to define the different heat sources induced by a deformation process. These sources are estimated from infrared data by using the local heat equation. The image processing involves Fourier techniques and its reliability is studied using spectral methods. An example of thermomechanical analysis of a rubberlike material illustrates the great interest of infrared data for improving behaviour models.