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Jayakumar, T.
- Characterization of Metallic Materials Through Elastic Properties
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Authors
T. Jayakumar
1,
Anish Kumar
1
Affiliations
1 Metallurgy and Materials Group, Indira Gandhi Centre for Atomic Research, Kalpakkam-603102, IN
1 Metallurgy and Materials Group, Indira Gandhi Centre for Atomic Research, Kalpakkam-603102, IN
Source
Journal of Pure and Applied Ultrasonics, Vol 36, No 2-3 (2014), Pagination: 29-35Abstract
The paper presents various studies carried out in the authors' laboratory for multi-scale microstructural characterization in different metallic structural materials such as nickel base alloys, zirconium alloys and titanium alloys through elastic properties. The elastic properties are evaluated at macroscale using ultrasonic velocity measurements and at micro/nano scale using atomic force acoustic microscopy. A thickness independent ultrasonic measurement based nondestructive methodology implemented for in-situ assessment of degradation of alloy 625 ammonia cracker tubes in heavy water plants is also discussed.Keywords
Elastic Property, Ultrasonic Velocity, Atomic Force Acoustic Microscopy, Microstructure.- Non Linear Elastic Properties and Ultrasonic Attenuation in Ni-Al-Cr Alloy
Abstract Views :197 |
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Authors
Affiliations
1 Physics Department, University of Allahabad, Allahabad-211002, IN
2 Indira Gandhi Centre for Atomic Research, Kalpakkam-603102, IN
1 Physics Department, University of Allahabad, Allahabad-211002, IN
2 Indira Gandhi Centre for Atomic Research, Kalpakkam-603102, IN
Source
Journal of Pure and Applied Ultrasonics, Vol 33, No 3 (2011), Pagination: 54-58Abstract
The single crystal higher order elastic constants of Ni-Al-Cr ternary alloy at different temperatures have been calculated with the help of interaction potential model. Ultrasonic attenuation in the ternary alloy is determined using higher order elastic constants. Other ultrasonic parameters such as Gruneisen numbers, acoustic coupling constants and acoustical anisotropy have been also calculated to discuss the ultrasonic properties of the ternary alloys. The ultrasonic wave propagation behavior at different temperatures for Ni-Al-Cr alloy have been investigated and correlated with respect to the microstructural phenomena during the wave propagation and thermal behavior of the ternary alloy. An ultrasonic mechanism has been developed to correlate the temperature dependent ultrasonic properties with the thermophysical properties particularly the thermal conductivity of the alloy. The results are compared with earlier studies of the elastic constants and are found to be in good agreement. We find that the thermal conductivity of Ni-Al-Cr alloy plays important role in the ultrasonic wave propagation behavior inside the alloy.Keywords
Ternary Alloy, Elastic Constants, Ultrasonic Attenuation, Thermal Properties.- Ultrasonic Internal Rotary Inspection System (IRIS) For Heat Exchanger and Steam Generator Tubes
Abstract Views :172 |
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Authors
Affiliations
1 Non-Destructive Evaluation Division, Indira Gandhi Centre for Atomic Research, Kalpakkam-603102, Tamil Nadu, IN
1 Non-Destructive Evaluation Division, Indira Gandhi Centre for Atomic Research, Kalpakkam-603102, Tamil Nadu, IN
Source
Journal of Pure and Applied Ultrasonics, Vol 31, No 1 (2009), Pagination: 24-30Abstract
Ultrasonic Internal Rotary Inspection System (IRIS) is used for inspection of tubes of heat exchangers and steam generators. The system displays circumferential cross section of tubes (wall thickness of tubes) at any given axial position and reveals both uniform and localised (pitting) corrosion. In this paper, the operating principle of IRIS and comparison of wall thickness measurements by physical and IRIS methods are briefly explained. Details of studies carried out on the resolution capabilities of IRIS in stainless steel and brass tubes having artificial defects (holes) are discussed. The results obtained from a study carried out on a carbon steel tube with artificial defects under baffle plate are also discussed in this paper.- Ultrasonic Nondestructive Characterisation of Nuclear Materials
Abstract Views :158 |
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Authors
Affiliations
1 Centre for Nano Science and Technology, K S Rangasamy College of Technology, Tiruchengode-637215, Tamil Nadu, IN
2 Indira Gandhi Centre for Atomic Research, Kalpakkam-603102, Tamil Nadu, IN
1 Centre for Nano Science and Technology, K S Rangasamy College of Technology, Tiruchengode-637215, Tamil Nadu, IN
2 Indira Gandhi Centre for Atomic Research, Kalpakkam-603102, Tamil Nadu, IN
Source
Journal of Pure and Applied Ultrasonics, Vol 34, No 4 (2012), Pagination: 69-71Abstract
Ultrasonic non-destructive evaluation (NDE) technique is a versatile and sensitive tool for structural/microstructural and defect characterisation of materials. An indigenous experimental set-up developed in the authors’ laboratory is used for online ultrasonic velocities and attenuation measurement over a wide range of temperatures from room temperature to 1100 K. The measured ultrasonic parameters such as ultrasonic velocities and derived elastic constants are used to assess changes in microstructural features as a function of temperatures. The first order differentials of the temperature dependent ultrasonic parameters are used to reveal the precise information about the structural/phase transitions. In the present investigation, ultrasonic longitudinal velocity measurements carried out in β-quenched Zircaloy-2 specimens in the temperature range of 298 to 623 K clearly reveal formation of intermetallic precipitates from the β-quenched martensite phase. It is observed that the first order differential plots of variation in ultrasonic velocity as function of temperature is an effective tool in predicting the temperatures at which the structural changes take place. In addition, the fatigue and the creep-fatigue damages in AISI 316 stainless steel are correlated with on-line ultrasonic velocity measurements, particularly made at elevated temperatures. The results reveal that in-situ high temperature ultrasonic measurements enable assessment of creep and fatigue damage with high sensitivity.Keywords
Ultrasonic Velocity, β-Quenched Zircaloy-2, AISI 316 L (N) Stainless Steel.- Assessment of Residual Stresses in a Carbon Steel Weld Pad Using Critically Refracted Longitudinal (LCR) Waves
Abstract Views :168 |
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Authors
Affiliations
1 Physics Department Anna University, Chennai-600025, IN
2 Non Destructive Evaluation Division, Indira Gandhi Centre for Atomic Research, Kalpakkam-603102, IN
1 Physics Department Anna University, Chennai-600025, IN
2 Non Destructive Evaluation Division, Indira Gandhi Centre for Atomic Research, Kalpakkam-603102, IN