SU1295326A1 - Method of ultrasonic quality control of articles - Google Patents

Abstract

The invention relates to non-destructive testing and can be used for ultrasonic testing of the quality of weakly absorbing single crystals. The aim of the invention is to increase the reliability and information content of the control by eliminating errors in the orientation of the ultrasonic transducer relative to the product. According to the method of ultrasonic quality control of products using an ultrasonic transducer when it is scanned, the research institutes and turning around its own axis emit pulses of ultrasonic vibrations and receive a series of echo pulses reflected from the opposite surface of the product. At each turn of the radiator, the envelope of the series of received pulses is determined, and the product quality and the nature of the defect are determined by the deviation of this envelope from the exponent. silt with S SL

Description

The invention relates to a non-destructive testing and can be used in the ultrasonic quality control of weakly absorbing single crystals.

The purpose of the invention is to increase the reliability and information content of the control by eliminating errors when turning the ultrasonic transducer.

The drawing shows a device for carrying out the proposed method.

The device contains a Pulse generator 1, an ultrasonic transducer 2, a receiving amplifier 3, an iKOToporo input is connected to the output of a pulse generator 1 and to an ultrasonic transducer 2, a two-channel oscilloscope 4, an exponential generator 5, a synchronizer 6, the first output of which is connected to the pulse generator 1 the second output of the synchronizer 6 is connected to the input of the generator 5 exponents, the third output of the synchronizer 6 is connected to the input of a two-channel oscilloscope 4, the input of the first channel of a two-channel oscilloscope 4 is connected to you ode receiving-th amplifier 3 and the input of the second two-channel oscilloscope channel 4 is connected to the output of the generator 5 exponent. The ultrasonic transducer 2 is acoustically connected to the controlled product 7,

The method of ultrasonic quality control of products is described as follows.

The high-frequency electric radio pulses produced by the pulse generator 1 are fed to an ultrasonic transducer 2, which emits pulses of ultrasonic shear vibrations into the monitored product 7. The ultrasonic pulses propagate in the controlled article 7, repeatedly reflecting from its plane-parallel opposite faces. The ultrasonic signals reflected from the opposite surface of the product 7 are received by the ultrasonic transducer 2, converted into electrical signals which are fed to

the input of the receiving amplifier 3, amplifiers, defects are absent. If

It reaches the required value, from the output of receiver 3 is fed to the input of one of the channels of a two-channel oscilloscope 4, on the screen of an electromotive series of received echo pulses differs from the exponent, then it is determined how the deviation of the envelope changes from the exponent at an incident beam. tubes that register them. The input of the second channel of the two-channel oscilloscope 4 is supplied with an exponential signal from the generator 5 of the exponent. The synchronizer 6 provides the start of the pulse generator 1, the generator 5 exponential generator and the scan generator of the two-channel oscilloscope 4 in such a way that

on the oscilloscope screen 4, simultaneously with a series of received echo pulses, an exponential signal is observed. Changing the time constant of the exponential signal, combine the latter with the vertices of the echo pulses of the received series.

The ultrasound signal is scanned over the volume of the monitored product 7 by moving the ultrasound transducer 2 along one of its plane-parallel faces. The position of the ultrasonic transducer 2 on the surface of the test product 7

They are determined by the coordinates of the own axis of the ultrasonic transducer 2 and the angle oi, which characterizes the direction of polarization of the shear vibrations excited by the ultrasonic BUM transducer 2 relative to any direction, such as the direction of polarization of the shear vibrations, in the initial position of the ultrasonic transducer - 2.

0

five

0

Ultrasonic transducer 2 is additionally rotated around its own axis ranging from zero to 90 in order to determine whether it changes and, if so, how, around a series of received echo pulses, depending on the angle of rotation of the ultrasonic transducer relative to its angle initial position If the envelope of the received echo pulses is exponential and does not change when the transducer 2 is rotated around its own axis at each point on the surface of the product when the ultrasound signal is scanned over the volume of the tested product 7, then there are no defects in the product. If

Since the envelope of a series of received echo pulses differs from the exponent, it is determined how the deviation of the envelope changes from the exponent when the transducer rotates around its own axis at each point on the surface of the product when the ultrasonic signal is scanned over the volume of the product being monitored, and the deviation can be judged on the nature of the defect. In cases where the envelope of a series of received echo pulses is exponential at a certain orientation of the transducer, and then when the transducer is rotated around its axis, it becomes interferential, the defect is internal mechanical stress. In cases where the envelope echoes Since the pulses remain interference when the transducer is rotated around its axis, a possible defect is the heterogeneity of the elastic properties of the product. By changing the deviation of the envelope; 1, it can receive echo pulses from the exponent as the transducer rotates around its axis.

0

five

0

Claims (1)

defects such as blockiness, foreign inclusions. Invention Formula The method of ultrasonic quality control of products, which means that an ultrasonic transducer is installed on the controlled product, emit ultrasonic vibration pulses, receive a series of echo pulses reflected from the opposite surface of the product, and determine the parameters of these pulses. the presence of a defect is made, so that, in order to increase the reliability and informativeness of the control, when scanning the product, the ultrasonic transducer is rotated around its own axis during the process of radiation and reception, the presence of the defect is determined by the deviation of the envelope of the series of the echo pulses from the exponent, and the nature of the defect - by the change in the deflection of the envelope. Editor O. Bugir Compiled by G. Fedorov Tehred A. Kravchuk, Order 613/52 Circulation 777 Subscription VNISh State Committee of the USSR for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5 Production and printing company, t. Uzhgorod, st. Project, 4 Proofreader N.Korol