Theory and application of ultrasonic microstructural characterization

Thompson, R. B.

doi:10.1007/bf03223168

Cited by 7 publications

(5 citation statements)

References 13 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Non-destructive testing (NDT), Non-destructive evaluation [17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32] (NDE) and Non-destructive inspection (NDI) are the techniques that are based [33][34][35][36][37][38][39][40][41][42][43] on the application of determining the characteristics of materials or components and for assessing life of the component by evaluating the detected inhomogeneities and harmful defects present in the component without impairing its usefulness. During service, many factors [17] like unanticipated stresses (residual and system), operation outside designed limits (excessive temperature and load cycling), operation and environmental effects, degradation of material properties in service, etc., which are difficult to predict, affect the designed life of the component.…”

Section: Non-destructive Evaluationmentioning

confidence: 99%

“…There is an ASTM standard E 588 titled 'Detection of large inclusions in bearing quality steel by ultrasonic method'. Also porosity [18] can be characterized.…”

Section: Examples Of Case Studies Carried Out For Assessment Of Compomentioning

confidence: 99%

“…Elastic moduli of pure metal are very low which will further increase with the addition of the alloying elements and during precipitation hardening. Ultrasonic velocity will be influenced [18] by the elastic moduli of the material which will be influenced by the precipitate forming elements. Information about microstructural induced changes in the elastic moduli can be deduced from the ultrasonic velocity by Equation 1:…”

Section: Ultrasonic Testingmentioning

confidence: 99%

See 2 more Smart Citations

Characterization of Intermetallic Precipitates in Ni-Base Alloys by Non-destructive Techniques

Acharya¹,

Ramesh²,

Murthy³

2015

Superalloys

View full text Add to dashboard Cite

The present industrial scenario requires all engineering structure to be designed considering stability of several parameters at the operating conditions e.g. Temperature, pressure, resistance to mechanical and surface degradation . Choice of materials for any engineering component should be such that it operates safely for reliable function, without failure during in-service, giving optimum component life. Due to scarcity of various resources and cost of manufacturing, regular maintenance and evaluation of structural integrity at every stage of production is necessary. Nondestructive techniques NDT , along with modern computational facility help in nonintrusive investigation of the component at regular intervals of the operating stages for many critical applications. This will result in increment of designed component life and also help in maximizing utilization of natural resources.For long, Ultrasonic has been associated with defect detection, but with the recent advances in electronics in combination with computational capabilities Ultrasonic velocity measurements have also been attempted for characterization of solutionising and precipitation behavior in various alloy systems such as aluminium alloys, ferritic steel, maraging steel, nickel base alloys and titanium alloys. "s the speed of sound in a homogeneous medium is directly related to both elastic modulus and density, any changes in elastic property with varying degree of inhomogeneities will affect in pulse transit time through a sample of given thickness. Due to variation in elastic modulus of the matrix in the alloy resulting from the various precipitates it has been attributed towards the change in ultrasonic velocity of the alloy and thereby resulting in popularization of Ultrasonic testing for online monitoring of the component. The precipitation hardening has been believed to arise from the formation of very small solute clusters which uses significant scattering of the conduction electron cause © 2015 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.during the rearrangement, while the formation of the precipitates resulting in variation of electrical resistivity of the aged alloy.In the present chapter, a few non-destructive techniques used to characterize different microstructural features and the precipitation behavior, evolved through various heat treatments using Direct Current Potential Drop DCPD technique for measuring electrical resistivity and Ultrasonic Testing for measurements of ultrasonic parameters are presented. Further, validation of the observed results on microstructural features is also presented through hardness and microscopy studies.Thus, this study in effect can be used for non-destructive evaluation of the microstructures.

show abstract

Section: Non-destructive Evaluationmentioning

confidence: 99%

“…There is an ASTM standard E 588 titled 'Detection of large inclusions in bearing quality steel by ultrasonic method'. Also porosity [18] can be characterized.…”

Section: Examples Of Case Studies Carried Out For Assessment Of Compomentioning

confidence: 99%

Section: Ultrasonic Testingmentioning

confidence: 99%

See 1 more Smart Citation

Characterization of Intermetallic Precipitates in Ni-Base Alloys by Non-destructive Techniques

Acharya¹,

Ramesh²,

Murthy³

2015

Superalloys

View full text Add to dashboard Cite

show abstract

“…The voids are then reduced in size until they are completely closed, at which time the rate of atomic diffusion is a maximum. This process is accomplished principally by interstitial or vacancy diffusion, depending upon the materials at the interface (1,2).…”

Section: Scope and Purposementioning

confidence: 99%

Ultrasonic evaluation of beryllium-copper diffusion bonds

Jamieson¹

2000

View full text Add to dashboard Cite

SummaryConventional peak amplitude ultrasonic techniques have proven to be unreliable when used to evaluate solid state bonds. Of particular concern are bonds of intermediate strength that would pass a typical ultrasonic examination. These are commonly called "kissing bonds." Several advanced ultrasonic techniques were compared to determine the best technique for predicting the bond strength of diffusion bonded beryllium-copper. After an extensive literature search, several advanced ultrasonic techniques were chosen for inclusion in this study. Integrated backscatter calculations, frequency domain reflection coefficients, and time-of-flight variance techniques, which showed varying degrees of success on other material interface systems, were compared in their ability to characterize the bond strength of twenty-two beryllium-copper diffusion bond samples with varying bond qualities. Modifications to previously reported time-of flight histogram and reflection coefficient techniques were also suggested and implemented as a part of this study.Correlation of integrated backscatter calculations and time-of-flight variance with bond strength was good for low, intermediate, and high strength bonds. Correlation of the slope of the frequency based reflection coefficient was poor when considering all bond strengths; however, some correlation was found for medium and high strength bonds. The Y-intercept of the frequency based reflection coefficient curve showed moderate correlation for all bond strengths. 2 Discussion Scope and PurposeDiffusion bonding is a joining process that is becoming increasingly popular as a metallurgical joining method, and offers many advantages over other processes such as fusion welding and brazing. It allows similar and dissimilar metals to be joined at temperatures that are not only far below their melting temperature, but in many cases below their heat treating and annealing ranges. It can also avoid the drastic changes in microstructure typically seen in and adjacent to fusion welds, and the numerous undesirable conditions that can occur during the solidification process. The diffusion bonding process involves applying pressure at an elevated temperature to two samples which have their mating surfaces prepared as flat and smooth as possible. Initially, diffusion begins where contact is made between the two surfaces at the highest points. As the pressure and heat are increased, plastic deformation causes the interface to transform into one of isolated voids, thus increasing the contact area and the rate of diffusion. The voids are then reduced in size until they are completely closed, at which time the rate of atomic diffusion is a maximum. This process is accomplished principally by interstitial or vacancy diffusion, depending upon the materials at the interface (1,2).The quality of a diffusion bond, as in other bonds, is of critical importance in ensuring the proper performance of the bond for its intended application. Nondestructive test methods, particularly ultrasonic techniques,...

show abstract

“…Using ultrasonic NDE techniques to estimate parameters characterizing the microstructure is a new development [36,37].…”

Section: ]mentioning

confidence: 99%

Ultrasonic monitoring of recrystallization: an example of in-situ process control with NDE

Liu

View full text Add to dashboard Cite

Theory and application of ultrasonic microstructural characterization

Cited by 7 publications

References 13 publications

Characterization of Intermetallic Precipitates in Ni-Base Alloys by Non-destructive Techniques

Characterization of Intermetallic Precipitates in Ni-Base Alloys by Non-destructive Techniques

Ultrasonic evaluation of beryllium-copper diffusion bonds

Ultrasonic monitoring of recrystallization: an example of in-situ process control with NDE

Contact Info

Product

Resources

About