National Research Council of Canada

Canadian Patents and Development Limited/societe Canadienne Des Brevets

American Iron and Steel Institute

Martin Lord

Jean-Pierre Monchalin

Daniel Levesque

Andre Moreau

Christian Padioleau

Jean F Bussiere

Guy Lamouche

Marc Dubois

A method is disclosed for evaluating the physical properties of a sample, for example, the grain size in a polycrystalline material. An ultrasound field is generated in a local region of the sample with a non-contact source, such as a pulsed laser, such that the generated ultrasound diffuses away from said local region. After waiting until the generated ultrasound field has reached a diffusion regime, the resulting ultrasound field is measured with a non-contact detector. Parameters are adjusted in a mathematical model describing the predicted behaviour of the ultrasound field in the diffusion regime to fit the detected ultrasound field to the mathematical model. In this way, parameters dependent on the physical properties of the sample, such as the diffusion coefficient and absorption coefficient, can be derived. The grain size, for example, can be estimated from these parameters preferably by calibrating the diffusion coefficient to grain size.

Apparatus and method for evaluating the physical properties of a sample using ultrasonics

Apparatus and method for detecting shear resonances includes structure and steps for applying a radiation pulse from a pulsed source of radiation to an object to generate elastic waves therein, optically detecting the elastic waves generated in the object, and analyzing the elastic waves optically detected in the object. These shear resonances, alone or in combination with other information, may be used in the present invention to improve thickness measurement accuracy and to determine geometrical, microstructural, and physical properties of the object. At least one shear resonance in the object is detected with the elastic waves optically detected in the object. Preferably, laser-ultrasound spectroscopy is utilized to detect the shear resonances.

Laser-ultrasound spectroscopy apparatus and method with detection of

The invention is concerned with a method and apparatus for measuring magnetic losses in a ferromagnetic material specimen. According to the invention, an alternating magnetic field having a predetermined frequency and an amplitude which is modulated at a frequency lower than the predetermined frequency is applied to the specimen, and a temperature modulation at a surface of the specimen having the applied field is measured. The magnitude of magnetic losses in the specimen is determined from the measured surface temperature modulation. The method and apparatus of the invention do not necessitate winding coils around the ferromagnetic material specimen, and also enable one to obtain information about the distribution of magnetic losses in the specimen.

Method and apparatus for measuring magnetic losses in ferromagnetic

Growing community of inventors

Beloeil, Canada

Martin Lord