Method for manufacturing ceramic samples for adjusting ultrasonic flaw detectors

Abstract

FIELD: production of control (tuning) samples from ceramic materials.SUBSTANCE: in order to create an artificial defect with given geometric parameters, a blind hole is made on the defect-free surface of a sample blank by removing material from the side of the hole to the depth of the defect. The ceramic sample blank is a segment made from an article similar to the one being tested, in which two blind flat-bottomed holes are made, for which the segment is installed and secured in a device that ensures grinding of the end edges of the segment at an angle of 30 to 55 degrees to the normal of the working surface, whereas the first end edge of the segment is ground on a grinding machine with a cutting depth of 0.01 mm to 0.06 mm, a transverse feed of 5 mm / stroke to 40 mm / stroke and a longitudinal feed of 5 m / min to 40 m / min, followed by making the first flat-bottomed hole on a milling machine from the side of the ground surface of the segment with a diamond drill with a diameter of 1 mm to 3 mm with a rotation speed of 1500 rpm to 3500 rpm and a feed of 0.06 mm / min to 1 mm / min, after which the segment is reinstalled and secured in the device for grinding the second end edge of the segment, then it is ground on a grinding machine with a cutting depth of 0.01 mm to 0.06 mm, a transverse feed of 5 mm / stroke to 40 mm / stroke and a longitudinal feed of 5 m / min to 40 m / min, followed by making a second flat-bottomed hole on a milling machine from the side of the ground surface of the segment with a diamond drill with a diameter of 1 mm to 3 mm with a rotation speed of 1500 rpm to 3500 rpm and a feed of 0.06 mm / min to 1 mm / min.EFFECT: creating control (tuning) samples that are as structurally similar as possible to the products being tested.1 cl, 9 dwg

Description

[0001] The invention relates to the field of non-destructive testing and can be used for the production of control (tuning) samples from ceramic materials (for example, quartz ceramics, glass ceramics), intended for adjusting the sensitivity and sweep of ultrasonic flaw detectors.

[0002] The proposed technical solution is intended for use in various industries that require non-destructive testing of ceramic products.

[0003] To ensure high reliability of non-destructive ultrasonic testing of ceramic products, ceramic reference (control) samples containing simulators of the defects being tested are required. These samples are designed to adjust ultrasonic flaw detectors during non-destructive testing of ceramic products for the presence of imperfections. These samples must be structurally similar (material, geometry, shape, surface roughness, etc.) to the products being tested.

[0004] A known method for fabricating a sample for adjusting the sensitivity of ultrasonic flaw detectors (SU 1202394 A1, IPC G01N 29 / 22, February 15, 1994) involves joining sample elements, one of which contains a defect model, using diffusion welding. To improve manufacturing quality, a layer no thicker than 0.0003 times the elastic wavelength of the sample is placed between the surfaces to be welded. The layer is made of a diffusion-activating material, and the welding is performed at the homogenization temperature of the sample material. A disadvantage of this method is the impossibility of diffusion welding ceramic materials and, consequently, the impossibility of its use in fabricating ceramic samples for adjusting ultrasonic flaw detectors.

[0005] A known method for producing flaw detection specimens (SU 787980 A1, IPC G01N 27 / 84, 15.12.1980) involves applying increasing force to the specimen until the required opening depth of an artificial defect is achieved. To improve the accuracy of defect parameters, artificial defects are created on the specimen surface before applying the increasing force. The specimen is heated in a neutral environment to the plastic deformation temperature of the specimen material. After applying increasing compressive force, the defect depth is mechanically processed to the specified depth. The main disadvantage of this method is its inability to produce specimens from ceramic materials, due to the impossibility of obtaining a defect with a specified opening under loading (since ceramics are a brittle material) and the lack of plastic deformation in ceramic materials.

[0006] The closest in technical essence is the method for producing a control specimen for flaw detection (SU 1307320 A1, IPC G01N 27 / 82, 30.04.1987), which consists of making a blind hole in the defect-free surface of the specimen blank and then irradiating the blank material to create an artificial defect. To create a gas-saturated zone with specified geometric parameters, the bottom of the hole is made parallel to the surface of the blank, the irradiation is carried out by gas saturation to a depth less than the hole depth, and a portion of the blank material is removed from the side of the hole to its depth.

[0007] The main disadvantage of this invention is the impossibility of modeling a defect in a ceramic sample blank by gas saturation of the ceramic material.

[0008] The technical result of the proposed invention is to increase the accuracy of sensitivity adjustment and scanning of ultrasonic flaw detectors during non-destructive testing of ceramic products by using ceramic samples manufactured in accordance with the described method.

[0009] The specified technical result is achieved in that a method is proposed for manufacturing ceramic samples for setting up ultrasonic flaw detectors, which consists in the fact that in order to create an artificial defect with specified geometric parameters on the defect-free surface of the sample blank, a blind hole is made by removing the material of the blank from the side of the hole to the depth of the defect, characterized in that the ceramic sample blank is a segment made from an article similar to the one being tested, in which two blind flat-bottomed holes are made, for which the segment is installed and secured in a device that ensures grinding of the end edges of the segment at an angle of 30 to 55 degrees to the normal of the working surface, wherein the first end edge of the segment is ground on a grinding machine with a cutting depth of 0.01 mm to 0.06 mm,transverse feed from 5 mm / stroke to 40 mm / stroke and longitudinal feed from 5 m / min to 40 m / min, followed by making the first flat-bottomed hole on the milling machine from the side of the ground surface of the segment with a diamond drill with a diameter of 1 mm to 3 mm with a rotation speed of 1500 rpm to 3500 rpm and a feed of 0.06 mm / min to 1 mm / min, after which the segment is reinstalled and secured in a device for grinding the second end edge of the segment, then it is ground on a grinding machine with a cutting depth of 0.01 mm to 0.06 mm, transverse feed from 5 mm / stroke to 40 mm / stroke and longitudinal feed from 5 m / min to 40 m / min, followed by making the second flat-bottomed hole on the milling machine from the side of the ground surface of the segment with a diamond drill with a diameter of 1 mm up to 3 mm with a rotation speed from 1500 rpm to 3500 rpm and a feed from 0.06 mm / min to 1 mm / min,

[0010] Fig. 1 shows a sketch of a sample (segment) 1 with two defect simulators (blind flat-bottomed holes) 2 with different angles of inclination of the bottom surfaces relative to the surface of the sample 1.

[0011] Fig. 2 schematically shows the installation of the sample blank 1 in the specialized fixture 3, where: 1 is the sample, 3 is the specialized fixture, 4 is the ground surface of the sample, 5 is the fixture support.

[0012] Fig. 3 and Fig. 4 show the external appearance of one of the manufactured samples 1, where 4 is the ground surface of the sample installed in a specialized device 3 using clamps 6.

[0013] Fig. 5 shows a diagram of the arrangement of the sample blank 1 in the specialized device 3 after its reinstallation, where: 1 is the sample (segment), 3 is the specialized device, 4 is the ground surface of the sample, 5 is the device support.

[0014] Fig. 6-9 show tomograms of the obtained samples 1 in the cross-section of the blind flat-bottomed holes (defect simulators) 2.

[0015] To ensure the structural similarity of control (tuning) samples 1 to the ceramic products being tested, they must be fabricated directly from the tested products, followed by mechanical processing of defect simulators (blind flat-bottomed holes) 2 with specified geometric parameters (diameter from 1 mm to 3 mm), with an inclination angle of the bottom surface of the blind hole to the normal of the sample working surface from 30 to 55 degrees. After fabrication of the sample blank (segment) 1, it is subjected to non-destructive testing to exclude the presence of defects in the material of the sample blank 1.

[0016] To adjust the sensitivity of the ultrasonic flaw detector on the control (tuning) sample 1, two input angles are used. Therefore, it is necessary to create two defect simulators (blind flat-bottomed holes) 2, each with a different inclination angle of its bottom surface relative to the normal to the working surface of the sample. The diameter of the holes 2 (from 1 mm to 3 mm) corresponds to the maximum permissible equivalent defect area, determined in accordance with the regulatory documentation (design documentation, specifications, etc.) for the ceramic product being tested.

[0017] To ensure the required inclination angle of the bottom surface of the blind hole 2 in the ceramic sample 1, it is installed in a specialized fixture 3, which ensures reliable fixation of the sample 1 during its mechanical processing on grinding and milling machines. Fig. 2 schematically shows the installation of the sample blank 1 in the specialized fixture 3 (1 - sample, 3 - specialized fixture, 4 - ground surface of the segment, 5 - fixture support). The design of the specialized fixture 3 ensures grinding of the surface of the manufactured ceramic sample at an angle of 30 to 55 degrees to the normal of the working surface of the sample. This makes it possible to make the bottom surface of the blind holes at the required angle. Fig. 3 and Fig. 4 show the external view of one of the manufactured ceramic samples, installed with the help of clamps 6 in the specialized fixture 3.After making a blind flat-bottomed hole 2 on the first end edge of segment 1, the sample blank 1 is reinstalled and secured in a specialized fixture 3, then the mechanical processing of the second end edge of segment 1 is repeated on a grinding and milling machine. Fig. 5 shows a diagram of the arrangement of the sample blank (segment) 1 in a specialized fixture 3 after its reinstallation (1 - sample, 3 - specialized fixture, 4 - ground surface of the sample, 5 - fixture support).

[0018] The material of ceramic sample 1 shall not contain any defects (cracks, chips, cavities, etc.) not provided for by the design of sample 1; therefore, in order to prevent their formation, mechanical processing shall be carried out according to the optimal mode determined experimentally. Mechanical processing of the first and second end edges of segment 1 (Fig. 2 and Fig. 5) on a grinding machine is carried out with a cutting depth of 0.01 mm to 0.06 mm, a transverse feed of 5 mm / stroke to 40 mm / stroke and a longitudinal feed of 5 m / min to 40 m / min. Mechanical processing on a milling machine is carried out with a diamond drill with a diameter of 1 mm to 3 mm at a drill rotation speed of 1500 rpm to 3500 rpm and a feed of 0.06 mm / min to 1 mm / min. Mechanical processing according to the specified modes allows to avoid the formation of defects in the ceramic sample 1 (for example, a violation of the continuity of the material).

[0019] Blind flat-bottomed hole 2 is made using a diamond drill with a diameter of 1 mm to 3 mm. This also helps prevent defects during the machining of segment 1, as a metal drill is not capable of producing hole 2 of the required quality in the ceramic material. The exact diameter of the diamond drill is selected based on the required testing sensitivity, as defined in the regulatory and technical documentation (design documentation, specifications, etc.) for the ceramic product being tested. The smaller the diameter of the drill and, consequently, the smaller the diameter of blind flat-bottomed hole 2, the higher the sensitivity of ultrasonic testing when setting up the ultrasonic flaw detector on a given ceramic sample 1.

[0020] The implementation of the claimed method is confirmed by the following examples.

[0021] Example 1. In a sample blank (segment) 1 with overall dimensions of 120×100×30 mm, made from a defect-free section of a glass-ceramic product similar to the tested products, two blind flat-bottomed holes 2 with a diameter of 1 mm and a depth of 3 mm were made. The absence of defects in glass-ceramic segment 1 was previously confirmed by non-destructive radiation testing methods. Segment 1 was installed and secured with clamps 6 in a specialized device 3, providing grinding of the first end edge of segment 1 at an angle of 30 degrees to the normal of the working surface, as shown in Fig. 2. Next, the first end edge of segment 1 was ground on a grinding machine with a cutting depth of 0.01 mm, a transverse feed of 5 mm / stroke and a longitudinal feed of 5 m / min.Then, on a milling machine, from the side of ground surface 4, a first blind flat-bottomed hole 2 with a diameter of 1 mm and a depth of 3 mm was made with a diamond drill of 1 mm in diameter with a rotation speed of 1500 rpm and a feed of 0.06 mm / min. Then, segment 1 was reinstalled and secured with clamps 6 in a specialized device 3, which ensures grinding of the second end edge of segment 1 at an angle of 45 degrees to the normal of the working surface in accordance with Fig. 5. Then, the second end edge of segment 1 was ground on a grinding machine with a cutting depth of 0.01 mm, a transverse feed of 5 mm / stroke and a longitudinal feed of 5 m / min. Then, on a milling machine, from the side of the ground surface 4, a second blind flat-bottomed hole 2 with a diameter of 1 mm and a depth of 3 mm was made with a diamond drill with a diameter of 1 mm at a rotation speed of 1500 rpm and a feed rate of 0.06 mm / min.After mechanical processing using the described method and non-destructive radiation testing, ceramic sample 1 was found to be free of defects. A tomogram of the resulting ceramic sample 1, manufactured from a defect-free section of a glass-ceramic product, in cross-section through two blind flat-bottomed holes (defect simulators) 2, is shown in Fig. 6.

[0022] Example 2. In a sample blank (segment) 1 with overall dimensions of 120 x 100 x 20 mm, made from a defect-free section of a quartz ceramic product similar to the tested products, two blind flat-bottomed holes 2 with a diameter of 3 mm and a depth of 3 mm were made. The absence of defects in segment 1 made of quartz ceramics was previously confirmed by non-destructive radiation testing methods. Segment 1 was installed and secured using clamps 6 in a specialized device 3, ensuring grinding of the first end edge of segment 1 at an angle of 35 degrees to the normal of the working surface, as shown in Fig. 2. Next, the first end edge of segment 1 was ground on a grinding machine with a cutting depth of 0.06 mm, a transverse feed of 40 mm / stroke and a longitudinal feed of 40 m / min.Then, on a milling machine, from the side of ground surface 4, a first blind flat-bottomed hole 2 with a diameter of 3 mm and a depth of 3 mm was made using a diamond drill with a diameter of 3 mm with a rotation speed of 3500 rpm and a feed of 1 mm / min. Then, segment 1 was reinstalled and secured with clamps 6 in a specialized device 3, which ensures grinding of the second end edge of segment 1 at an angle of 50 degrees to the normal of the working surface in accordance with Fig. 5. Then, the second end edge of segment 1 was ground on a grinding machine with a cutting depth of 0.06 mm, a transverse feed of 40 mm / stroke and a longitudinal feed of 40 m / min. Then, on a milling machine, from the side of the ground surface 4, a second blind flat-bottomed hole 2 with a diameter of 3 mm and a depth of 3 mm was made using a diamond drill with a diameter of 3 mm with a rotation speed of 3500 rpm and a feed rate of 1 mm / min.After mechanical processing using the described method and non-destructive radiation testing, ceramic sample 1 was found to be free of defects. Tomograms of the resulting ceramic sample, fabricated from a defect-free section of a quartz ceramic product, in cross-sections of blind flat-bottomed holes (defect simulators) are shown in Fig. 7 and Fig. 8.

[0023] Example 3. In a sample blank (segment) 1 with overall dimensions of 110 x 90 x 20 mm, made from a defect-free section of a quartz ceramic product similar to the tested products, two blind flat-bottomed holes 2 with a diameter of 1.5 mm and a depth of 3 mm were made. The absence of defects in segment 1 made of quartz ceramics was previously confirmed by non-destructive radiation testing methods. Segment 1 was installed and secured using clamps 6 in a specialized device 3, ensuring grinding of the first end edge of segment 1 at an angle of 45 degrees to the normal of the working surface, as shown in Fig. 2. Next, the first end edge of segment 1 was ground on a grinding machine with a cutting depth of 0.04 mm, a transverse feed of 25 mm / stroke and a longitudinal feed of 25 m / min.Then, on a milling machine, from the side of ground surface 4, a first blind flat-bottomed hole 2 with a diameter of 1.5 mm and a depth of 3 mm was made with a diamond drill of 1.5 mm in diameter at a rotation speed of 2500 rpm and a feed of 0.6 mm / min. Then, segment 1 was reinstalled and secured with clamps 6 in a specialized device 3, which ensures grinding of the second end edge of segment 1 at an angle of 55 degrees to the normal of the working surface in accordance with Fig. 5. Then, the second end edge of segment 1 was ground on a grinding machine with a cutting depth of 0.04 mm, a transverse feed of 25 mm / stroke and a longitudinal feed of 25 m / min. Then, on a milling machine, from the side of the ground surface 4, a second blind flat-bottomed hole 2 with a diameter of 1.5 mm and a depth of 3 mm was made using a diamond drill with a diameter of 1.5 mm at a rotation speed of 2500 rpm and a feed rate of 0.6 mm / min.After mechanical processing using the described method and non-destructive radiation testing, ceramic sample 1 was found to be free of defects. A tomogram of the resulting ceramic sample 1, manufactured from a defect-free section of a quartz ceramic product, in a cross-section through two blind flat-bottomed holes (defect simulators) 2 is shown in Fig. 9.

[0024] The proposed method for producing ceramic samples 1 for adjusting ultrasonic flaw detectors has the following advantages:

[0025] 1. Allows the production of control (tuning) samples 1 from ceramic materials for adjusting the sensitivity of ultrasonic flaw detectors in accordance with the requirements of GOST R ISO 16811-2016 "Ultrasonic testing. Adjustment of sensitivity and range" (in a structurally similar design), which allows for increased testing accuracy by increasing the reliability of the adjustment.

[0026] 2. The use of the specified mechanical processing modes when making a blind flat-bottomed hole 2 in the sample blank (segment) 1 allows to avoid the formation of defects (cracks, cavities, chips, etc.) in them, and also allows to maintain the required geometric dimensions of the manufactured defect imitators (blind flat-bottomed holes) 2: the diameter of the hole 2 (the area of ​​the reflective surface), the angle of inclination of the bottom surface.

Claims

A method for manufacturing ceramic samples for adjusting ultrasonic flaw detectors, which consists in the fact that in order to create an artificial defect with specified geometric parameters on the defect-free surface of the sample blank, a blind hole is made by removing the material of the blank from the side of the hole to the depth of the defect, characterized in that the ceramic sample blank is a segment made from an article similar to the one being tested, in which two blind flat-bottomed holes are made, for which purpose the segment is installed and secured in a device that ensures grinding of the end edges of the segment at an angle of 30 to 55 degrees to the normal of the working surface, wherein the first end edge of the segment is ground on a grinding machine with a cutting depth of 0.01 mm to 0.06 mm,transverse feed from 5 mm / stroke to 40 mm / stroke and longitudinal feed from 5 m / min to 40 m / min, followed by making the first flat-bottomed hole on the milling machine from the side of the ground surface of the segment with a diamond drill with a diameter of 1 mm to 3 mm with a rotation speed of 1500 rpm to 3500 rpm and a feed of 0.06 mm / min to 1 mm / min, after which the segment is reinstalled and secured in a device for grinding the second end edge of the segment, then it is ground on a grinding machine with a cutting depth of 0.01 mm to 0.06 mm, transverse feed from 5 mm / stroke to 40 mm / stroke and longitudinal feed from 5 m / min to 40 m / min, followed by making the second flat-bottomed hole on the milling machine from the side of the ground surface of the segment with a diamond drill with a diameter of 1 mm up to 3 mm with a rotation speed from 1500 rpm to 3500 rpm and a feed from 0.06 mm / min to 1 mm / min,

Images