Method for testing samples and materials for hydroabrasive wear and device for implementing it

Abstract

FIELD: testing equipment.SUBSTANCE: sample is installed on a support pipe and secured with clamps, the liquid is supplied under constant working pressure through a nozzle, the abrasive is dosed by ejection from a hopper through a vacuum tube, the wear products and spent abrasive are removed through a conical drain into a settling tank, whereas each test cycle is carried out with a single use of clean water and new abrasive, and the hydroabrasive jet is formed vertically through the nozzle.EFFECT: increase in the accuracy of the test results.3 cl, 2 dwg

Description

[0001] The group of inventions relates to the field related to testing equipment and is used to conduct research on materials and samples for hydroabrasive wear.

[0002] A known method for testing materials for hydroabrasive wear (SU1196729A) utilizes a horizontal jet of an abrasive mixture and water. The method involves feeding the working medium through sealed containers separated by elastic membranes that compensate for static pressure to stabilize the flow rate. The abrasive mixture and water enter a mixer, after which the horizontal jet is directed at the sample secured in the working chamber. Adjusting the pressure in the lower volumes of the containers allows for control of the intensity of the impact.

[0003] A disadvantage of this method is the horizontal jet direction, which leads to an uneven distribution of abrasive particles due to their settling under gravity and reduces the accuracy of wear assessment. Furthermore, the system requires precise pressure synchronization in the tanks, which complicates setup and increases the risk of errors. The fixed jet geometry limits the ability to simulate real-world operating conditions, such as variable angles of attack or turbulent flows. Another disadvantage is the manual adjustment of parameters, which increases the time required for test preparation and execution.

[0004] A known method for testing materials for hydroabrasive wear (RU2444719) consists of exposing samples fixed in a chamber to a hydroabrasive jet using a rotating disk with channels into which liquid and abrasive particles are supplied.

[0005] The disadvantage of this method is the uneven distribution of the aggressive medium over the working surface of the sample and the inability to regulate the angle of attack and the distance from the working surface to the nozzle, as well as the entry of wear products of the samples and secondary abrasive particles that have lost their integrity and aggressive properties into the working chamber with the liquid medium, which reduces the accuracy of the material wear assessment.

[0006] A known method for testing samples for hydroabrasive wear is RU2444719C2, which includes installing samples in a chamber, exposure to a jet of liquid with an abrasive and chemical additives, and also constantly separating the used particles from the liquid to supply new ones.

[0007] A disadvantage of this method is the complexity of the separation and filtration system, which requires an additional cleaning process, increasing the test cycle time. Another disadvantage of this method is a significant reduction in measurement accuracy, as it does not ensure uniform distribution of the abrasive jet over the sample surface, the lack of adjustment of the attack angle, and the fixed distance to the sample.

[0008] The closest technical solution is a device for testing materials for hydroabrasive wear (RU53777U1), which consists of a specimen clamp with a mechanism for its movement, a hydroabrasive head with adjustable distance to the specimen and attack angle from 0° to 90°. The hydroabrasive nozzle has a supply for both liquid and abrasive, with the liquid supplied by a pump, as well as a single hopper for settling the abrasive and filtering the liquid for subsequent use.

[0009] A design flaw of the device is its inability to provide adequate filtration of liquid from crushed abrasive particles with a cleavage surface, as well as previous test products that differ in size and hardness from the stated abrasive criteria. Removing used abrasive and wear debris from the settling tank is difficult and labor-intensive. The use of separating mesh as filters complicates the water purification process. The secondary impact of wear debris negatively impacts measurement results.

[0010] The technical problem solved by the claimed group of inventions is to increase the accuracy of the results of the tests carried out, as well as to reduce the time spent on testing samples for hydroabrasive wear.

[0011] The technical result of increasing the accuracy of test results is achieved by eliminating secondary impacts of abrasive and wear debris. This, in turn, is ensured by the effective removal of wear debris and abrasive particles from the attack area due to the vertical position of the hydroabrasive jet. At the same time, the angle of attack can be varied by rotating the support supporting the test specimen. Furthermore, easy access to the device's main components, a telescopic frame design that allows for setting a convenient testing height, and a chamber design with a minimal number of components reduce the test cycle time.

[0012] Fig. 1 shows a general device for testing samples for hydroabrasive wear.

[0013] Fig. 2 shows the test area.

[0014] The testing device consists of a working chamber 1 designed to prevent the dispersion of liquid containing the abrasive component, a pressure source 3 connected to the water supply system, on which a pressure gauge 4 is located to determine the system pressure, and a tank 5 containing an abrasive 6, into which a vacuum tube 7 is installed for collecting the abrasive. The vacuum tube 7 is connected to an abrasive supply hose 8. Chamber 1 is mounted on a telescopic frame 9 for convenient height adjustment. Inside the chamber 1 there is a support frame 10, on which a rotary support 11 is installed, due to which it is possible to change the angle of attack of the abrasive jet on the sample 2. In the upper part of the chamber 1, a high-pressure water supply tube 13 with an ejection chamber 12 is installed in a special hole, in which, when water passes under pressure, a vacuum is formed and is transferred through the sleeve 8 to the vacuum tube 7, entraining the abrasive 5.To enable adjustment of the distance between the test specimen 2 and the nozzle 20, a clamping attachment 14 is installed on the chamber 1, which secures the water supply tube 13. At the end of the water supply tube 13, a valve 15 is installed for turning on and off the supply of a liquid medium with an abrasive into the working area, connected by a high-pressure hose 19 to the pressure source 3. A support pipe 17 with holes for adjusting the extension of the clamps 16 relative to the length of the test specimen is attached to the rotary support 11. A conical drain 18 is located under the chamber 1.

[0015] The proposed method is implemented as follows: Pressure source 3 is connected to the water supply system, after which, with tap 15 closed, high-pressure hose 19 is connected to water supply pipe 13. Abrasive 6 is poured into hopper 5, and test sample 2 is weighed on an electronic scale with an accuracy of up to four decimal places. Test sample 2 is then placed on support pipe 17 in working chamber 1, positioned relative to nozzle 20, and secured with two clamps 16 using bolts. After this, the required angle of attack of the abrasive jet is set using the rotary support 11. The required distance from the sample 2 to the nozzle 20 is set using the clamping attachment 14. Chamber 1 is closed with a lid, the pressure source 3 is turned on, and valve 15 is opened. When the liquid passes through the ejection chamber 12, a vacuum is created, which draws the abrasive along with it through the vacuum tube 7 in the hopper 5.The hydroabrasive jet passing through nozzle 20 impacts specimen 2 and washes away wear debris and abrasive particles from the attack area, draining through a conical drain into a settling tank. This prevents secondary impact and the ingress of destroyed abrasive and test material particles onto the specimen. At the end of the test cycle, pressure source 3 is disconnected and valve 15 is closed after releasing the pressure in high-pressure hose 19. Open chamber lid 1, release clamps 16, and remove specimen 2 from support pipe 17. Rinse, dry, and weigh it on the same scale with an accuracy of four decimal places. After the test cycle, water is drained from the settling tank and the abrasive is removed. Specimen wear is determined by relative mass loss. This process is repeated three or more times to obtain a statistical sample of the data.

[0016] The telescopic frame (9) ensures high mobility and functionality of the setup. Its modular design allows for quick disassembly and assembly, simplifying transportation to test sites, including labs and production facilities. The telescopic height adjustment mechanism allows for convenient positioning of the working chamber (1) at the desired angle and level, which is especially important when working with samples of varying sizes. The minimal number of frame components reduces assembly and setup time and the risk of failure. This allows for faster test preparation, reducing the overall test cycle time. The compact and simple design also facilitates storage and maintenance, making it suitable for use in confined spaces.

[0017] The claimed group of inventions for testing samples and materials for hydroabrasive wear was designed, manufactured, and the method was tested at the Kola Branch of the Bauman Moscow State Technical University.

[0018] The studies of wear-resistant deposited coating by the method and on the device of the claimed group of technical solutions were carried out under the following parameters: Working fluid - water; Water flow rate - 10 l / min; Head pressure - 1.2 MPa; Working pressure - 14 MPa; Distance to sample - 10 mm; Test cycle duration - 10 min; Attack angle - 90°; Abrasive consumption per cycle - 20 kg.

[0019] River sand GOST 8736-93 was used as an abrasive, the abrasive hardness was 6-8 on the Mohs scale.

[0020] The following data were obtained from the test results: the initial weight of the sample was 98.6168g, after the test cycle, its weight was 98.3028g, thus the relative weight loss was 0.314g. When repeating the test cycles, the following results were obtained: 98.3110g and 98.3066g, showing a relative weight loss of 0.3058g and 0.3102g, respectively.

Claims

1. A method for conducting hydroabrasive wear tests, which consists of the following sequence of operations: the pressure source is connected to the water supply system, after which, with the tap closed, the high-pressure hose is connected to the water supply pipe, abrasive is poured into the hopper, the test sample is weighed on an electronic scale with an accuracy of up to 4 decimal places, after which the test sample is placed on a support pipe in the working chamber, which is positioned relative to the nozzle and fixed with two clamps, after which the required angle of attack of the abrasive jet is set using a rotary support, the required distance from the sample to the nozzle is set using a clamping attachment, the chamber is closed with a lid, the pressure source is turned on, the tap is opened, when liquid passes through the ejection chamber, a vacuum is created, which draws the abrasive along with it through the vacuum tube in the hopper,the hydroabrasive jet passing through the nozzle impacts the sample and washes away wear products with abrasive particles from the attack area, flowing through a conical drain into a settling tank, which eliminates secondary impact and the ingress of destroyed abrasive and particles of the test material onto the sample, at the end of the test cycle, the pressure source is switched off and the pressure in the high-pressure hose is released, the chamber lid is opened, the clamps are released and the sample is removed from the support surface, washed, dried and weighed on the same scales with an accuracy of up to 4 decimal places, after the test cycle, water is drained from the settling tank and the abrasive is removed, the wear of the sample is determined by the relative loss of mass, the process is repeated 3 or more times to obtain a statistical sample of data.

2. A device for testing samples and materials for hydroabrasive wear, consisting of a working chamber designed to prevent the dispersion of liquid with an abrasive component, a pressure source connected to the water supply system, on which a pressure gauge is located for determining the pressure in the system, a hopper with an abrasive, in which a vacuum tube is installed for collecting the abrasive, wherein the vacuum tube is connected to a sleeve for feeding the abrasive, and the chamber is mounted on a telescopic frame with the ability to adjust the height, inside the chamber there is a support frame on which a rotary support is mounted, made with the ability to change the angle of attack of the abrasive jet on the sample, in the upper part of the chamber a high-pressure water supply tube with an ejection chamber is installed in an opening in which, when water passes under pressure, a vacuum is formed and is transmitted through the sleeve into the vacuum tube, entraining the abrasive, a clamping attachment is installed on the chamber,fixing the water supply tube and configured to adjust the distance between the test sample and the nozzle, a tap is installed on the water supply tube for turning on and off the supply of a liquid medium with an abrasive into the working area, connected by a high-pressure hose to a pressure source, a support pipe with holes for adjusting the extension of the clamps relative to the length of the test sample is attached to the rotary support, and a conical drain is located under the chamber.

3. The device according to paragraph 2, characterized in that the working chamber and frame are made collapsible.

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