Centre Technique Des Industries Mecaniques

Centre Technique Des Industries Mechaniques

Alain Lambert

Christian Flambard

Miguel Sancho Pavon

Marie-Claude Deblaere

A method of non-destructively testing materials comprises directing an incident beam of ultrasonic waves onto the surface of a material and detecting the beam reflected by the surface, the angle of incidence and the wavelength of the ultrasonic waves being detected, and the critical angle of incidence at which the energy of the reflected beam passes through a minimum being determined for at least two different wavelengths. A curve is then prepared showing how the critical angle or a quantity dependent thereon varies with the wavelength or a quantity dependent thereon. Apparatus for carrying out the method comprises a goniometer for transmitting the incident ultrasonic beam and detecting the reflected beam, means for varying the angle of incidence of the beam, means for varying the wavelength of the waves, and means for determining the critical angles of incidence. The invention is applicable inter alia to the testing of tempered steel components.

Non-destructive testing of materials using ultrasonic waves

This invention relates to a device for non-destructive measurement of the extent to which a surface layer of a material has been affected by a superficial treatment. The device has an emitter of ultrasonic waves and a receiver therefor, the emitter and receiver being movable over the arcuate surface of a semi-cylindrical block which is applied to the material being studied. The emitter and receiver can be moved until the ultrasonic beam is reflected by the surface of the material and measured, means being provided for precise measurement of the angle formed between the emitter and receiver.

Device for non-destructive measurement of a surface layer of a material

Angles and angular displacements of ultrasonic beams are measured by using a probe to transmit the beam to a point on a surface, particularly the surface of material being subjected to non-destructive examination, from which the beam is reflected to a receiving probe which may or may not be the same device as the transmitting probe. The length of the path traversed by the beam is varied in accordance with a relationship determined as a function of the angular displacement of the beam from an axis normal to the surface, and the time taken to traverse the path is detected. The variation in the length of the path may be effected by adjusting the separation of the transmitting probe from the surface while the probe is being angularly adjusted to vary the angular displacement of the beam, a fixed mirror being provided to return the beam by way of the point to the probe. Alternatively an angularly adjustable transmitting probe may direct the beam to the point and a separate probe which is both axially and angularly adjustable arranged to receive the relfected beam. In a third alternative, the transmitting probe directs the beam to the point by way of an adjustable mirror, a fixed mirror being arranged to return the beam by way of the point and the adjustable mirror to the probe.

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Creil, France

Alain Lambert