Defect detecting method for weak joint of diffusion welding joint interface

A connection interface and defect detection technology, which is applied in the direction of using sound waves/ultrasonic waves/infrasonic waves to analyze solids, etc., can solve problems such as unreliable weak joint defect detection methods, difficulty in distinguishing, and mixed reflected waves

Inactive Publication Date: 2014-09-03
HEILONGJIANG UNIVERSITY OF SCIENCE AND TECHNOLOGY
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Problems solved by technology

For diffusion welded joints of the same material, the ultrasonic waves produce very weak reflected waves on tiny weak joint defects; The interface also generates reflection waves, and the defect reflection waves are mixed with the interface reflection waves, making it difficult to distinguish and further increase the difficulty of detection. At present, there is no reliable detection method for weak joint defects

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  • Defect detecting method for weak joint of diffusion welding joint interface
  • Defect detecting method for weak joint of diffusion welding joint interface
  • Defect detecting method for weak joint of diffusion welding joint interface

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Embodiment Construction

[0025] The present invention will be described in more detail below with examples in conjunction with the accompanying drawings.

[0026] combine figure 1 , the specific implementation steps of the present invention are as follows:

[0027] (1) combination figure 2 , the ultrasonic transducer 1 is used to vertically incident the ultrasonic wave from the top of the diffusion welding sample 2 to the diffusion welding sample 2, and the ultrasonic transducer 1 is used to receive the ultrasonic reflected wave, expressed as N is the number of sampling points. The received ultrasonic reflected wave includes both the reflected wave on the upper surface of the diffusion welding sample 2 and the reflected wave at the connection interface of the diffusion welding sample 2.

[0028] (2) Using the window function d(n) to receive the ultrasonic reflected wave Perform truncation processing to intercept the reflected wave of the connection interface of diffusion welding sample 2, expre...

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Abstract

The invention provides a defect detecting method for a weak joint of a diffusion welding joint interface, aiming at solving the problem that the defect on the weak joint cannot be judged by the traditional ultrasonic wave detecting method. The defect detecting method comprises the steps of analyzing information concealed in Fourier transform spectrum phase of a weak joint defect signal in a frequency domain, and reflecting positive and negative wave Fourier transform spectrum phases as reference by utilizing an unwelded lower surface of an upper-layer sample; by judging the differences and similarities between the positive and negative wave Fourier transform spectrum phases reflected by a joint interface of a diffusion welding sample and the positive and negative wave Fourier transform spectrum phases reflected by the unwelded lower surface of the upper-layer sample, extracting defect phase jump information of the weak joint, establishing a phase jump function, and judging the defect of the weak joint according to the criterion. According to the defect detecting method for the weak joint of the diffusion welding joint interface, the defect of the weak joint can be correctly judged, and the problem that an ultrasonic wave detection method is difficult to judge the defect only according to a time domain signal is solved.

Description

technical field [0001] The invention relates to a method for detecting a welding interface, in particular to a method for detecting a weak joint defect at a diffusion welding connection interface. Background technique [0002] Diffusion welding is an advanced solid-phase welding method. The base metal does not need to be melted during welding, and the surfaces of the materials to be welded are in contact with each other. Under certain temperature and pressure, microscopic plastic deformation or microscopic The liquid phase expands the physical contact of the surface to be welded, and the welding method realizes the combination through the interdiffusion of atoms for a long time. Diffusion welding has the advantages of welding difficult-to-miscible materials, small surface plastic deformation, and uniform joint composition and structure. Typical defects of the diffusion bonding interface are lack of fusion, weak joints and microscopic holes. Weak joint defects seem to be we...

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): G01N29/04
Inventor 栾亦琳刚铁
Owner HEILONGJIANG UNIVERSITY OF SCIENCE AND TECHNOLOGY
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