ISSN:1058-9759    

DOI:10.1080/02780898908952948

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Recent developments in the field of Barkhausen signal measurements are reviewed. New highly sensitive measurements are discussed. Stress-induced Barkhausen jumps and recent applications in the field of nondestructive and destructive testing are evaluated.

ISSN:1058-9759    

DOI:10.1080/02780898908952949

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Studies of the interrelation of metallurgical and magnetic properties of high strength pearlitic steels are described. High voltage Lorentz electron microscopy has been used to identify directly the pinning sites for domain boundaries. The results lead via a physical model to a formula which permits the prediction of coercivity from the metallurgical microstructure. The empirical relationship suggested by Kneppo is found to describe well the virgin magnetization curve for a range of steels including those heat treated. It is shown that weld renormalization leads to magnetic parameters almost indistinguishable from the parent plate. Heat input variations do not significantly affect the magnetic properties.

ISSN:1058-9759    

DOI:10.1080/02780898908952950

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

A pulsed laser ultrasonic source has been used, in conjunction with finite-sized electromagnetic-acoustic transducers as detectors, to produce wide bandwidth waveforms in metals. These have been compared successfully to theory, and it has been shown that waveforms may also be obtained at elevated temperatures.

ISSN:1058-9759    

DOI:10.1080/02780898908952951

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Proven applications presently exist for Barkausen noise. They include for instance the NDT evaluation of residual stress and detection of stress related defects such as grinding burns. Commercially available instrumentation enables fast and repeatable measurements both in laboratory and field.

ISSN:1058-9759    

DOI:10.1080/02780898908952952

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Longitudinal and shear wave velocities were measured in gold-tungsten composites, of varying tungsten concentration. Different methods, including echo-overlap and cross-correlation were employed. Simple theoretical models were used to calculate the velocities. The calculated values agree reasonably with the experimental data. It would seem possible to determine the concentration of tungsten powder in gold bars by measuring the ultrasonic velocities

ISSN:1058-9759    

DOI:10.1080/02780898908952953

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Application of the Sablik-Jiles magnetomechanical theory to various NDE techniques for measuring stress in steels is reviewed. Among the techniques discussed are (1) differential anhysteretic susceptibility, (2) higher order harmonic amplitudes of the hysteretic magnetic flux density, (3) magabsorption, which involves measurement of the rf impedance of a coil coupled to a ferromagnetic material, and (4) Barkhausen measurements.

ISSN:1058-9759    

DOI:10.1080/02780898908952954

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

This paper describes an application of modern methods of computational electromagnetics to the problem of eddy-current nondestructive evaluation (NDE). Specifically, a volume integral equation is developed that can be used to model eddy-current probes with ferrite cores, or it can be used to compute flaw-field interactions. Both of these problems are of considerable importance in applying electromagnetic techniques to NDE, for they are intimately involved in detecting flaws and inverting eddy-current data for reconstructing flaws.

ISSN:1058-9759    

DOI:10.1080/02780898908952955

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

ISSN:1058-9759    

DOI:10.1080/02780898908952956

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor