Method for nondestructive evaluation of residual stress levels in aluminum alloy forged piece through ultrasonic waves

An internal residual stress, aluminum alloy technology, applied in the direction of measuring force, measuring device, instrument, etc., can solve the problems of irregular deformation of large aluminum alloy forgings, insufficient residual stress elimination, affecting product qualification rate, etc., and achieve a large measurement depth. , the effect of fast measurement speed and short measurement time

Active Publication Date: 2014-09-17
AVIC BEIJING INST OF AERONAUTICAL MATERIALS
View PDF6 Cites 24 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, due to the lack of a means of non-destructive measurement of residual stress during the solid solution process, the existing residual stress relief process lacks a reference basis and the residual stress relief is insufficient, which in turn causes large aluminum alloy forgings to appear unsatisfactory in subsequent processing. Deformation of rules affects product qualification rate
[0003] The traditional methods of non-destructive evaluation of residual stress are mainly X-ray method and Barkhausen noise method, but their penetration depth is relatively shallow. The depth does not exceed 0.3mm
The cause of irregular deformation during processing is mainly the residual stress inside the forging, which can only be measured by neutron diffraction at present, but this method requires huge equipment investment and the cost is too high

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0056] A large aluminum alloy forging of 7A85, 2000mm long, 1000mm wide, and 250mm thick. The detection steps are as follows:

[0057] (1) Select the probe

[0058] 1.1 Select the probe

[0059] Use a polarized transverse wave probe that emits vertically, and select the chip diameter and frequency of the probe according to the thickness of the aluminum alloy forging to be tested. The principle of selection is that the amplitude of the second bottom wave of the ultrasonic wave emitted by the probe is not less than the first when it propagates in the aluminum alloy forging. 20% of the amplitude of the bottom wave, if this requirement is not met, it is necessary to select a probe with a larger crystal diameter or a lower frequency until this condition is met;

[0060] 1.2 Optional couplant

[0061] Use a special couplant that matches the probe, so that the probe is firmly fixed on the surface of the forging to be tested, and at the same time ensure that the probe does not deta...

Embodiment 2

[0081] A large aluminum alloy forging of 7A85, 500mm long, 400mm wide, and 300mm thick. The detection steps are as follows:

[0082] (1) Select the probe

[0083] 1.1 Select the probe

[0084] Use a polarized transverse wave probe that emits vertically, and select the chip diameter and frequency of the probe according to the thickness of the aluminum alloy forging to be tested. The principle of selection is that the amplitude of the second bottom wave of the ultrasonic wave emitted by the probe is not less than the first when it propagates in the aluminum alloy forging. 20% of the bottom wave amplitude, if this requirement is not met, it is necessary to select a probe with a larger crystal diameter or a lower frequency until this condition is met;

[0085] 1.2 Optional couplant

[0086] Use a special couplant that matches the probe, so that the probe is firmly fixed on the surface of the forging to be tested, and at the same time ensure that the probe does not detach from t...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

No PUM Login to view more

Abstract

The invention belongs to the field of nondestructive detection and relates to a method for nondestructive evaluation of residual stress levels in an aluminum alloy forged piece through ultrasonic waves. According to the method, the phenomenon that the propagation speed of the ultrasonic waves in materials can be affected by stress in the materials to a certain extent is used, and the difference of residual stress levels among different positions in the large size aluminum alloy forged piece is reflected through changes of sound speeds. The method has the advantages of being high in detection speed, large in measuring depth, good in economy and the like. The residual stress in the large size aluminum alloy forged piece is measured through the sound elastic effect of the ultrasonic waves in the method, and the method has the advantages of being high in measuring speed, convenient to use, flexible in measuring range, good in economy and the like. The single-time measuring time of the method is about five minutes and is shorter that the single-time measuring time of a neutron diffraction residual stress measuring method, the detection speed is high, the maximum measuring depth of the method can reach 400 mm, is larger that the measuring depth of the neutron diffraction method, and is much larger that the measuring depth of an X-ray method or a Barkhausen noise method.

Description

technical field [0001] The invention belongs to the field of non-destructive testing and relates to a method for ultrasonic non-destructive evaluation of the internal residual stress level of aluminum alloy forgings. Background technique [0002] In order to meet the requirements of mechanical properties, large aluminum alloy forgings need to be treated with solid solution and aging. During the solid solution process, due to the large size of the forgings, there is a large difference in the cooling rate of each part during the rapid cooling process, resulting in different Uniform shrinkage deformation brings large residual stress. Although residual stress can be eliminated to a certain extent by processes such as cold pressing, pre-stretching, and aging, the effect of these processes on residual stress is related to the initial residual stress level, and different residual stress states require different elimination processes. However, due to the lack of a means of non-dest...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
Patent Type & Authority Applications(China)
IPC IPC(8): G01L1/25
Inventor 王晓史亦韦梁菁李国爱杨平华
Owner AVIC BEIJING INST OF AERONAUTICAL MATERIALS
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap