An ultrasonic coupling assembly includes a barrier layer that contacts the wall, and a generally thicker layer formed of a compliant material such as zinc foil that extends over the first layer. A third layer may cover and enclose the compliant layer, e.g., by folding the first layer over and on top of the second layer to cover the edge faces thereof. An exemplary embodiment is implemented using gold foil approximately one mil thick for the first layer, and zinc sheeting approximately four mils thick for the second layer. Use of inert top and bottom, or outside, layers prevents the inadvertent installation of the coupling element with the compliant layer directly contacting the wall. Disk embodiments may employ a stack of separate disks formed of foils or sheets of the respective materials. For cryogenic applications, a material such as indium may be used for the second layer without risk of its alloying or migration through the first layer.

Layered ultrasonic coupler

An ultrasonic probe includes an ultrasonic transducer; a delay line acoustically coupled to said transducer so that ultrasonic vibrations may be transmitted into said delay line from said ultrasonic transducer in a first direction, said delay line includes a first section and a second section; the first and second sections forming an interface that is substantially perpendicular to said first direction; and the second section including a surface for coupling with a material to be investigated. The probe can be used to measure a thickness of a coating on a substrate by transmitting a signal in a first direction from the transducer into the delay line; measuring a time t 1 for a first portion of the signal to travel round trip from the transducer and the interface; using the measured time t 1 to calculate an expected time t 2 for a second portion of the signal to travel round trip from the transducer to an opposite face of the delay line; measuring a time t 3 that it takes for a third portion of the signal to travel round trip from the transducer and an interface between the coating and the substrate; and calculating a thickness of the coating based on a difference between the time t 2 and the time t 3 .

Delay line for an ultrasonic probe and method of using same

An ultrasonic testing method uses surface waves to prevent false detection of primary cracks, to lower the level of structural noises from grain boundaries, and to improve the detectability in the ultrasonic testing by surface wave testing of hot rolling rolls A surface wave probe 10 capable of transmitting and receiving a surface wave is provided with a piezoelectric element 10A, a resin wedge 10C disposed on the front surface of the piezoelectric element 10A and a damping block 10B disposed on the back surface The surface wave probe 10 is driven to produce a short pulse having a pulse length being at most 25 times the wavelength of the surface wave to be produced A coupling liquid medium is supplied to the probe 10 in accordance with the peripheral speed of the roll to be tested Depending on the height of the reflected waves measured, the grinding allowance of the roll is determined, and the roll is ground according to the thus-determined grinding allowance The roll may be tested while being partly ground, and the optimum grinding allowance of the roll may be determined

Method and apparatus for ultrasonic testing of the surface of columnar structures, and method for grinding rolls by use of them

PROBLEM TO BE SOLVED: To provide an ultrasonic probe for high temperature capable of improving ultrasonic transmission property and enhancing in yield with enhancing adhesiveness of piezoelectric element, and provide its manufacturing method. SOLUTION: In a manufacturing process, in a state that the rotating of a pressing member 30 to a pedestal 12 around the axis is restrained, it is possible to press a heat resistance energizing member 20 with rotating a supporting means 29 around the axis and moving it in the axis direction, so that a pressing member 18 does not rotate even if the supporting means 29 is being rotated. With this, slipping does not occur mutually between a second electrode 14b, a piezoelectric element 16, a first electrode 14a and the pedestal 12, so that the adhesiveness among them is kept. Moreover, predetermined accurate load can be applied to the electrode from the outside, an accurate load is sustained by the supporting means 29, so that always accurate load can be continuously applied to the electrode. COPYRIGHT: (C)2009,JPO&INPIT

Ultrasonic probe for high temperature and its manufacturing method

A method of ultrasonically detecting a flaw on the surface of a circular cylinder by using a surface wave, aiming at preventing the over-detection of primary cracks, reducing the level of noise from a grain boundary and improving the flaw detecting performance. Specifically, a method of ultrasonically detecting a flaw on a hot rolled product by using a surface wave, comprising providing a surface wave probe (10), which is adapted to transmit and receive the surface wave, with a resin wedge (10C) on an ultrasonic wave-receiving surface of an ultrasonic oscillator (10A), and a damping member (10B) on the rear surface of the supersonic oscillator (10A), generating short pulses the width of which is not more than 2.5 times as large as the wavelength of the surface wave, supplying a medium liquid in accordance with a peripheral speed of the roll, grinding the roll on the basis of a grinding volume determined in accordance with the height of a reflected wave, and determining an optimum level of the roll grinding volume by detecting a flaw while partially grinding the roll.

Method and apparatus for ultrasonically detecting flaw on surface of circular cylinder, and method of grinding roll utilizing the same

A probe for ultrasonic flaw detectors includes a transducer and either a protection plate to protect the transducer or a metallic part for attaching the transducer directly to the object to be tested for flaws, these two parts being bonded to each other with a heat-resisting brazing or soldering material. Because of its high bonding strength, the probe thus formed is not only capable of serving both in high and low temperature ranges, but also may be used in a roving mode or in a stationary mode in testing the object.

Probe for ultrasonic flaw detectors

PURPOSE: To obtain a damper material having high acoustic impedance and large in the attenuation of sound, by providing a mixing process, a heating process and a compacting process. CONSTITUTION: A powder mixture 3 is obtained by mixing a high m.p. metal powder 1 and a low m.p. metal powder 2 and cavities are considerably left therein. Subsequently, only the powder 2 is melted by heating the powder 3 to the m.p. of the powder 2 and the places occupied by the powder 2 are converted to cavities by the powder 2 having flowed out. Along with this, the molten powder 2 flows in the mutual narrow parts of the powder 1 by a capillary action. The powder 2 flowing in the powder 1 plays a role like lubricant when said powder is compressed by external force as shown by an arrow and sling is generated in the powder 1. The powder 3 is compacted at high density and cooled and solidified by air or water cooling to obtain a material, that is, a damper material. In this case, the damper material especially prepared by mixing a tungsten powder and a lead powder is large in the attenuation of sound because of a mixture of metals largely different in acoustic impedance. By this method, the excellent damper material can be obtained. COPYRIGHT: (C)1988,JPO&Japio

Manufacture of damper material for probe

PURPOSE:To enable measurement of a minute change in a surface wave sound velocity by determining the incident angle theta of an ultrasonic wave giving a minute sound pressure reflectiv ity with the occurrence of a surface wave and by determining the surface wave sound velocity CRS = C/sin theta from the incident angle theta and a sound velocity C in a known shoe. CONSTITUTION:In a state wherein the contact surface 14 with a specimen 1 to be inspected of a shoe 17 of each of probes 20 of which incident angles theta are changed variously is not brought into contact with the specimen 1, and ultrasonic wave is transmitted from a vibrator 18, reflected at a point (e) of intersection and received by a vibrator 19, and thereby a reflected sound pressure E0 serving as a reference is measured beforehand for each of the probes 20. Next, in a state wherein the contact surface 14 of the shoe 17 is brought into contact with the same place of the specimen 1 sequentially, the ultrasonic wave is transmitted from the vibrator 18, reflected at the point (e) of intersection and received by the vibrator 19, a reflected sound pressure E1 on a different-material interface is measured for each of the probes 20, and a sound pressure reflectivity E1/E0 is determined. Subsequently, reflectivities E1/E0 are compared with one another and the incident angle theta of the ultrasonic wave giving the minimum of the reflectivities E1/E0 accompanying occurrence of a surface wave is deter mined. Then a surface wave sound velocity CRS of the specimen 1 to be inspected can be determined by CRS = C/sin theta.

Method and device for measuring ultrasonic sound velocity

PURPOSE: To make stable measurement at a high temp. by forming the contact medium of materials which are mixed with B 2 O 3 , SiO 2 or Al 2 O 3 , P 2 O 5 , and alkaline metal oxide (M 2 O) at ratios of a specific range and melt or cause a viscosity change in a specific temp. range. CONSTITUTION: The contact medium is formed of the materials which are the compsn. components contg. the B 2 O 3 in the range of 0 to 60wt.%, the SiO 2 or Al 2 O 3 of 0 to 40wt.%, the P 2 O 3 of 20 to 70wt.%, and the M 2 O of 8 to 70wt.% and melt or cause a viscosity change and half liquefy or liquefy in the temp. range of about 0 to 700°C. This medium may be made into a water-soluble or half water-soluble medium formed by dissolving or suspending the medium into an org. solvent or is made into solid as well by dissolving the medium in water or org. solvent and resting the solvent or dissolving the medium by heating in the org. solvent. A stable ultrasonic flaw detection is executed even at a high temp. in excess of about 300°C by applying this contact medium be tween a test body and a probe. In addition, the use of this medium as the con tact medium for transversal waves having excellent workability is also possible. COPYRIGHT: (C)1992,JPO&Japio

Takahiro Arakawa

Papers

Probe for ultrasonic flaw detectors

Manufacture of damper material for probe

Method and device for measuring ultrasonic sound velocity

Contact medium for ultrasonic flaw detection