A diamond strength testing device and method

Abstract

The present invention discloses a diamond strength testing device and method, and belongs to the technical field of superhard materials. The diamond strength test includes a PCD cavity and an ultrasonic vibration source, wherein the PCD upper pressure head is located in the PCD cavity and the upper end is fixed on the ultrasonic vibration source, and the PCD lower pressure head is located in the PCD cavity and the lower end is fixed on the ultrasonic vibration source. The present invention provides a diamond strength testing method, and the steps of the method are as follows: placing a diamond sample in an oven for drying; loading the dried diamond sample into the PCD cavity for testing; the diamond sample vibrates under the action of ultrasonic waves to achieve collision and wear between particles; and performing strength testing and evaluation on the diamond sample after ultrasonic crushing. The in-situ crushing of diamond particles by the present invention avoids the problem of large force deviation caused by particle size, is closer to the actual use state of diamond, and the device is simple to operate, convenient to clamp, disassemble and clean, and improves the test efficiency.

Description

Technical Field

[0001] The invention belongs to the technical field of superhard materials, and in particular relates to a diamond strength testing device and method. Background Art

[0002] Diamond is the hardest substance known so far. Diamond abrasives are widely used in grinding, lapping and polishing of materials such as stone, ceramics, glass and silicon wafers. Diamond abrasives include coarse abrasive grains and micro powders: coarse diamond abrasive grains refer to abrasive grains with a particle size of 16 / 18~325 / 400 mesh, which are the main raw materials for tools and products such as diamond grinding wheels, cutting discs and wire saws; micro diamond powder refers to particles with a particle size finer than 36 / 54 microns, which are widely used in diamond tools such as polycrystalline diamond, electroplated diamond wire and dicing knives.

[0003] Diamond is the "teeth of industry". Its anti-breakage "strength" is one of the important indicators of diamond abrasives, which directly affects the processing efficiency and service life. If the strength of the diamond abrasive itself is low, the grinding effect cannot be effectively exerted and it will break or wear out prematurely, resulting in a short product life; if the strength of the abrasive itself is too high, the self-sharpening property is poor, resulting in product grinding passivation and reduced processing efficiency. Therefore, the appropriate strength range is a key indicator of diamond abrasives.

[0004] At present, there are many methods for testing the strength of diamond coarse abrasive particles, including static compressive strength and impact toughness of abrasives in a free state. There is no fixed and effective test method for the strength of diamond micropowder. Users usually directly evaluate it based on the terminal processing efficiency and quality. The industry has been exploring suitable test methods for the strength of diamond micropowder. Zhou Bo and others tried to use Raman spectroscopy to determine the crystal structure, internal defects and impurity content of the micropowder to achieve the strength grade classification of diamond micropowder. Cai Lei and others tried to use impact toughness to distinguish the strength grades of diamond micropowder.

[0005] However, there are many problems with the above test methods: (1) When diamond abrasives are used for bonded grinding, they are ground and crushed in situ under certain dynamic forces. The static pressure strength and impact toughness in the free state are used to characterize the strength of diamond coarse abrasive grains. Raman spectroscopy can only detect the microstructure and internal defects of the particles in a static state. The above methods cannot effectively reflect the actual performance and effect of abrasives in diamond products and tools. (2) The evaluation of diamond strength by terminal processing performance has a lag on the one hand, and on the other hand, the grinding performance is greatly affected by factors such as formulation, process, and use environment, and the evaluation is one-sided. (3) The impact toughness test system has defects such as poor stability, complex operation, and difficulty in cleaning. The impact toughness test is achieved by colliding an 8mm steel ball with the abrasive in an impact tank. The size and hardness of the two are quite different, which easily results in dead corners and impurities introduced by excessive wear of the steel ball, thus affecting the stability of the test system. Secondly, the device requires tooling such as plugs and nuts, which are complicated to clamp and disassemble. In addition, the nuts are easy to loosen during the impact process, which may even cause powder leakage and sample spillage. During the impact process, large particles are easily impacted by the steel ball, while small particles are easy to be placed in dead corners and avoid impact, resulting in the impact result failing to reflect the state of the entire particle group, which deviates greatly from the state in which almost every abrasive particle is subjected to force during the actual use of the abrasive. In addition, after the impact, the powder adheres to the inner wall of the tank and the surface of the steel ball, making the tank difficult to clean. (4) The compressive strength and impact toughness tests are inefficient and prone to human errors. At present, the compressive strength of coarse abrasive particles needs to be clamped one by one, which is extremely inefficient, and the particle crushing still relies on empirical judgment. The plugs at both ends of the impact tank of the impact test are gradually worn out to form pits under the impact of the steel ball, and the impact plugs need to be replaced regularly, which affects the test efficiency and increases the test cost.

[0006] The current impact test system can only calibrate the impact frequency, but cannot measure and calibrate dynamic parameters such as the number of impacts and stroke, making it difficult to trace the entire measurement system. Summary of the invention

[0007] In view of the deficiencies in the above-mentioned background technology, the present invention proposes a diamond strength testing device and method, which uses ultrasonic vibration to crush diamond particles in situ under pre-pressure, avoiding the problem of large force deviation caused by particle size and being closer to the actual use state of diamond.

[0008] In order to achieve the above object, the present invention provides the following technical solutions:

[0009] A diamond strength testing device comprises a PCD cavity and an ultrasonic vibration source, wherein a PCD upper pressure head is located in the PCD cavity and the upper end is fixed on the ultrasonic vibration source, a PCD lower pressure head is located in the PCD cavity and the lower end is fixed on the ultrasonic vibration source, and the PCD cavity, the PCD upper pressure head and the PCD lower pressure head form a closed structure.

[0010] The present invention provides a diamond strength testing method, the specific steps are as follows:

[0011] ①Put the diamond sample in an oven for drying;

[0012] ②Insert the PCD lower indenter into the PCD mold cavity, then install the diamond sample dried in step ① into the PCD mold cavity, install the PCD upper indenter, and apply pressure at both ends of the PCD upper indenter and the PCD lower indenter to compact the diamond sample;

[0013] ③ Turn on the ultrasonic system to make the diamond sample vibrate under the action of ultrasound to achieve collision and wear between particles, and obtain the diamond sample after ultrasonic crushing;

[0014] ④ Carry out strength test and evaluation on the diamond sample after ultrasonic crushing in step ③.

[0015] Preferably, in step ①, the diamond sample is dried at a temperature of 105-115° C. and for a drying time of 2-4 h.

[0016] Preferably, in step ②, the mass of the diamond sample in the PCD mold cavity is 0.3-2.0 g.

[0017] Preferably, in step ②, after the diamond sample is compacted, the PCD upper indenter and the PCD lower indenter cannot move relative to each other.

[0018] Preferably, in step ③, the ultrasonic output power is 1000-2000W, the ultrasonic frequency is 20-40KHz, and the ultrasonic time is 1-8min.

[0019] Preferably, in step ④, when the diamond sample is diamond coarse abrasive grains, the diamond coarse abrasive grain size is 16 / 18~325 / 400 mesh; the diamond coarse abrasive grains are screened to detect the mass change rate φ of the basic grains before and after ultrasonic crushing to evaluate their strength, φ=(m 0 -m 1 )*100 / m 0 ; The φ is negatively correlated with the strength value of the diamond coarse abrasive grains, and the higher the φ value is, the lower the strength value of the diamond coarse abrasive grains is.

[0020] Preferably, in step ④, when the diamond sample is diamond powder, the particle size of the diamond powder is ≤36 / 54 μm; the diamond powder is evaluated for its strength by the mobility δ of D90 before and after ultrasonic crushing; the D90 is the particle size corresponding to the cumulative volume fraction of 90% when detected by a laser particle size analyzer, δ=(D90 前 -D90 后 )*100 / D90 前; The δ value is negatively correlated with the diamond strength value, and the higher the δ value, the lower the strength value of the diamond powder.

[0021] The beneficial effects of the present invention are as follows:

[0022] 1. The diamond strength testing device disclosed in the present invention is wear-resistant and has a prolonged replacement cycle; it is simple to operate, and is convenient to clamp, disassemble and clean, thereby improving the testing efficiency; the testing device utilizes ultrasonic vibration to achieve collisions between particles, thereby avoiding the problem of impurities introduced by steel ball collisions and the generation of impact dead angles, and there are corresponding metrological calibration methods and specifications for parameters such as ultrasonic power and ultrasonic frequency, so the testing device can ensure the reliable stability of the testing system.

[0023] 2. The PCD material used in the diamond strength testing device disclosed in the present invention has a hardness equivalent to or even higher than that of diamond, which prolongs the service life of the device and reduces or even avoids a series of problems caused by the traditional testing method using metal materials with a hardness far lower than that of diamond.

[0024] 3. The present invention provides a diamond strength testing method, which is to use ultrasonic vibration to in-situ crush diamond particles under a certain pre-pressure, avoiding the problem of large force deviation caused by particle size and being closer to the actual use state of diamond.

[0025] 4. The present invention adopts D90 mobility to characterize the diamond micropowder. When the diamond abrasive is working, almost all particles participate in the process. Therefore, using the cumulative volume fraction of 90% to characterize the diamond micropowder can better show the overall changes. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying any creative work.

[0027] Figure 1 It is a schematic structural diagram of the diamond strength testing device of the present invention.

[0028] In the figure: 1-PCD mold cavity, 2-PCD upper pressure head, 3-PCD lower pressure head, (4, 4')-ultrasonic vibration source. DETAILED DESCRIPTION

[0029] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0030] Example 1

[0031] A diamond strength testing device comprises a PCD cavity and an ultrasonic vibration source, wherein a PCD upper pressure head is located in the PCD cavity and the upper end is fixed on the ultrasonic vibration source, a PCD lower pressure head is located in the PCD cavity and the lower end is fixed on the ultrasonic vibration source, and the PCD cavity, the PCD upper pressure head and the PCD lower pressure head form a closed structure.

[0032] Example 2

[0033] A diamond strength testing method, the specific steps are as follows:

[0034] ① Place the diamond sample in an oven for drying.

[0035] ②Insert the PCD lower pressure head into the PCD mold cavity, then load the diamond sample dried in step ① into the PCD mold cavity, install the PCD upper pressure head, and apply pressure at both ends of the PCD upper and lower pressure heads to compact the diamond sample.

[0036] ③ Turn on the ultrasonic system to allow the diamond sample to vibrate under the action of ultrasonic waves to achieve collision and wear between particles.

[0037] ④ Carry out strength test and evaluation on the diamond sample after ultrasonic crushing in step ③.

[0038] For diamond coarse abrasive grains, the screening method is used to detect the mass change rate of the basic grains before and after ultrasonic crushing to evaluate its strength, φ = (m 0 -m 1 )*100 / m 0 , φ is negatively correlated with the strength value of diamond coarse abrasive grains. The higher the φ value, the lower the strength value of diamond coarse abrasive grains.

[0039] The strength of diamond powder is evaluated by the mobility δ of D90 before and after ultrasonic crushing. D90 is the particle size corresponding to 90% of the cumulative volume fraction of the particles when detected by the laser particle size analyzer. δ = (D90 前 -D90 后 )*100 / D90 前 , the δ value is negatively correlated with the diamond strength value. The higher the δ value, the lower the strength value of the diamond powder.

[0040] Example 3

[0041] A diamond strength testing device comprises a PCD cavity and an ultrasonic vibration source, wherein a PCD upper pressure head is located in the PCD cavity and the upper end is fixed on the ultrasonic vibration source, a PCD lower pressure head is located in the PCD cavity and the lower end is fixed on the ultrasonic vibration source, and the PCD cavity, the PCD upper pressure head and the PCD lower pressure head form a closed structure.

[0042] A diamond strength testing method, the specific steps are as follows:

[0043] ① Place the diamond sample in an oven at 105-115°C for 2-4 hours.

[0044] ②Insert the PCD lower indenter into the PCD mold cavity, then load the diamond sample dried in step ① into the PCD mold cavity, install the PCD upper indenter, and apply pressure at both ends of the PCD upper and lower indenters to compact the diamond sample. The PCD upper indenter and the PCD lower indenter cannot move relative to each other.

[0045] ③ Turn on the ultrasonic system, set the ultrasonic output power to 1000-2000W, the ultrasonic frequency to 20-40KHz, and the ultrasonic time to 1-8min, so that the diamond can vibrate under the action of ultrasound to achieve collision and wear between particles.

[0046] ④ Carry out strength test and evaluation on the diamond sample after ultrasonic crushing in step ③.

[0047] Among them, the diamond coarse abrasive grain size is 16 / 18~325 / 400 mesh. The screening method is used to detect the basic grain mass change rate φ before and after ultrasonic crushing to evaluate its strength, φ=(m 0 -m 1 )*100 / m 0 , φ is negatively correlated with the strength value of diamond coarse abrasive particles. The higher the φ value, the lower the strength value of diamond coarse abrasive particles. For diamond micropowder with a particle size of ≤36 / 54μm, the mobility δ of D90 before and after ultrasonic crushing is used to characterize the strength grade. D90 is the particle size corresponding to 90% of the cumulative volume fraction of particles when detected by laser particle size analyzer. δ=(D90 前 -D90 后 )*100 / D90 前 , the δ value is negatively correlated with the strength value. The higher the δ value, the lower the strength value of the diamond powder.

[0048] Example 4

[0049] A diamond micro powder strength testing method, the specific steps are as follows:

[0050] ① Place the diamond sample in an oven and dry it at 110°C for 3 hours. Use a laser particle size analyzer to measure the D90 of the sample, which is marked as D90. 前 .

[0051] ②Install the PCD lower indenter into the PCD cavity, then load 0.5g of diamond powder (type 2 crushed material) sample with a particle size of 6 / 12μm into the PCD cavity, install the PCD upper indenter, and apply pressure at both ends of the PCD upper and lower indenters to compact the diamond sample.

[0052] ③ Turn on the ultrasonic system, set the ultrasonic power to 2000W, the vibration frequency to 20KHz, and the ultrasonic vibration time to 3min, so that the diamond can vibrate under the action of ultrasound to achieve collision and wear between particles.

[0053] ④ Take out the diamond sample after ultrasonic crushing in step ③ from the tank, measure the particle size distribution of the sample after vibration with Malvern laser particle size analyzer, record the D90 data, and mark it as D90 后 .

[0054] Diamond powder D90 of the present invention 前 =11.597μm, D90 后 =8.269μm, using the formula δ=(D90 前 -D90 后 )*100 / D90 前 Calculation was performed and the D90 mobility δ was 28.7%.

[0055] Example 5

[0056] A diamond micro powder strength testing method, the specific steps are as follows:

[0057] ① Place the diamond sample in an oven and dry it at 105°C for 5 hours. Use a laser particle size analyzer to measure the D90 of the sample, which is marked as D90. 前 .

[0058] ②Install the PCD lower indenter into the PCD cavity, then load 1g of diamond powder (raw material) sample with a particle size of 20 / 30μm into the PCD cavity, install the PCD upper indenter, and apply pressure at both ends of the PCD upper and lower indenters to compact the diamond sample.

[0059] ③ Turn on the ultrasonic system, set the ultrasonic power to 2000W, the vibration frequency to 30KHz, and the ultrasonic vibration time to 2min, so that the diamond can vibrate under the action of ultrasound to achieve collision and wear between particles.

[0060] ④ Take out the diamond sample after ultrasonic crushing in step ③ from the tank, measure the particle size distribution of the sample after vibration with Malvern laser particle size analyzer, record the D90 data, and mark it as D90后 .

[0061] Diamond powder D90 of the present invention 前 =29.526μm, D90 后 =16.771μm, using the formula δ=(D90 前 -D90 后 )*100 / D90 前 Calculation was performed and the D90 mobility δ was 43.2%.

[0062] Example 6

[0063] A diamond micro powder strength testing method, the specific steps are as follows:

[0064] ① Place the diamond sample in an oven and dry it at 105°C for 5 hours. Use a laser particle size analyzer to measure the D90 of the sample, which is marked as D90. 前 .

[0065] ②Install the PCD lower indenter into the PCD cavity, then load 0.5g of diamond powder (2.5 type crushed material) sample with a particle size of 5 / 10μm into the PCD cavity, install the PCD upper indenter, and apply pressure at both ends of the PCD upper and lower indenters to compact the diamond sample.

[0066] ③ Turn on the ultrasonic system, set the ultrasonic power to 2000W, the vibration frequency to 20KHz, and the ultrasonic vibration time to 3min, so that the diamond can vibrate under the action of ultrasound to achieve collision and wear between particles.

[0067] ④ Take out the diamond sample after ultrasonic crushing in step ③ from the tank, measure the particle size distribution of the sample after vibration with Malvern laser particle size analyzer, record the D90 data, and mark it as D90 后 .

[0068] Diamond powder D90 of the present invention 前 =9.840μm, D90 后 =8.216μm, using the formula δ=(D90 前 -D90 后 )*100 / D90 前 The D90 mobility δ was calculated to be 16.5%.

[0069] Example 7

[0070] A diamond micro powder strength testing method, the specific steps are as follows:

[0071] ① Place the diamond sample in an oven and dry it at 105°C for 5 hours. Use a laser particle size analyzer to measure the D90 of the sample, which is marked as D90. 前 .

[0072] ② Install the PCD lower indenter into the PCD cavity, then load 1g of diamond powder (type 3 crushed material) sample with a particle size of 8 / 16μm into the PCD cavity, install the PCD upper indenter, and apply pressure at both ends of the PCD upper and lower indenters to compact the diamond sample.

[0073] ③ Turn on the ultrasonic system, set the ultrasonic power to 2000W, the vibration frequency to 20KHz, and the ultrasonic vibration time to 3min, so that the diamond can vibrate under the action of ultrasound to achieve collision and wear between particles.

[0074] ④ Take out the diamond sample after ultrasonic crushing in step ③ from the tank, measure the particle size distribution of the sample after vibration with Malvern laser particle size analyzer, record the D90 data, and mark it as D90 后 .

[0075] Diamond powder D90 of the present invention 前 =15.549μm, D90 后 =13.387μm, using the formula δ=(D90 前 -D90 后 )*100 / D90 前 The D90 mobility δ was calculated to be 13.9%.

[0076] Example 8

[0077] A diamond micro powder strength testing method, the specific steps are as follows:

[0078] ① Place the diamond sample in an oven and dry it at 105°C for 5 hours. Use a laser particle size analyzer to measure the D90 of the sample, which is marked as D90. 前 .

[0079] ②Install the PCD lower indenter into the PCD cavity, then load 0.4g of diamond powder (type 2 crushed material) sample with a particle size of 15 / 25μm into the PCD cavity, install the PCD upper indenter, and apply pressure at both ends of the PCD upper and lower indenters to compact the diamond sample.

[0080] ③ Turn on the ultrasonic system, set the ultrasonic power to 1000W, the vibration frequency to 40KHz, and the ultrasonic vibration time to 6min, so that the diamond can vibrate under the action of ultrasound to achieve collision and wear between particles.

[0081] ④ Take out the diamond sample after ultrasonic crushing in step ③ from the tank, measure the particle size distribution of the sample after vibration with Malvern laser particle size analyzer, record the D90 data, and mark it as D90 后 .

[0082] Diamond powder D90 of the present invention 前=24.894μm, D90 后 =19.218μm, using the formula δ=(D90 前 -D90 后 )*100 / D90 前 Calculation was performed and the D90 mobility δ was 22.8%.

[0083] Example 9

[0084] A diamond micro powder strength testing method, the specific steps are as follows:

[0085] ① Place the diamond sample in an oven and dry it at 105°C for 5 hours. Use a laser particle size analyzer to measure the D90 of the sample, which is marked as D90. 前 .

[0086] ②Install the PCD lower indenter into the PCD cavity, then load 0.4g of diamond powder (1.5 type crushed material) sample with a particle size of 0 / 1μm into the PCD cavity, install the PCD upper indenter, and apply pressure at both ends of the PCD upper and lower indenters to compact the diamond sample.

[0087] ③ Turn on the ultrasonic system, set the ultrasonic power to 1000W, the vibration frequency to 40KHz, and the ultrasonic vibration time to 8min, so that the diamond can vibrate under the action of ultrasound to achieve collision and wear between particles.

[0088] ④ Take out the diamond sample after ultrasonic crushing in step ③ from the tank, measure the particle size distribution of the sample after vibration with Malvern laser particle size analyzer, record the D90 data, and mark it as D90 后 .

[0089] Diamond powder D90 of the present invention 前 =0.787μm, D90 后 =0.545μm, using the formula δ=(D90 前 -D90 后 )*100 / D90 前 The D90 mobility δ was calculated to be 30.7%.

[0090] Example 10

[0091] A diamond micro powder strength testing method, the specific steps are as follows:

[0092] ① Place the diamond sample in an oven and dry it at 110°C for 3 hours. Use a laser particle size analyzer to measure the D90 of the sample, which is marked as D90. 前 .

[0093] ②Install the PCD lower indenter into the PCD cavity, then load 0.4g of diamond powder (type 1 crushed material) sample with a particle size of 4 / 8μm into the PCD cavity, install the PCD upper indenter, and apply pressure at both ends of the PCD upper and lower indenters to compact the diamond sample.

[0094] ③ Turn on the ultrasonic system, set the ultrasonic power to 1000W, the vibration frequency to 40KHz, and the ultrasonic vibration time to 8min, so that the diamond can vibrate under the action of ultrasound to achieve collision and wear between particles.

[0095] ④ Take out the diamond sample after ultrasonic crushing in step ③ from the tank, measure the particle size distribution of the sample after vibration with Malvern laser particle size analyzer, record the D90 data, and mark it as D90 后 .

[0096] Diamond powder D90 of the present invention 前 =7.832μm, D90 后 =4.120μm, using the formula δ=(D90 前 -D90 后 )*100 / D90 前 The D90 mobility δ was calculated to be 47.4%.

[0097] Embodiment 11

[0098] A diamond micro powder strength testing method, the specific steps are as follows:

[0099] ① Place the diamond sample in an oven and dry it at 115°C for 2 hours. Use a laser particle size analyzer to measure the D90 of the sample, which is marked as D90. 前 .

[0100] ②Install the PCD lower indenter into the PCD cavity, then load 0.6g of diamond powder (type 2 crushed material) sample with a particle size of 8 / 16μm into the PCD cavity, install the PCD upper indenter, and apply pressure at both ends of the PCD upper and lower indenters to compact the diamond sample.

[0101] ③ Turn on the ultrasonic system, set the ultrasonic power to 2000W, the vibration frequency to 40KHz, and the ultrasonic vibration time to 8min, so that the diamond can vibrate under the action of ultrasound to achieve collision and wear between particles.

[0102] ④ Take out the diamond sample after ultrasonic crushing in step ③ from the tank, measure the particle size distribution of the sample after vibration with Malvern laser particle size analyzer, record the D90 data, and mark it as D90 后 .

[0103] Diamond powder D90 in this example 前 =16.477μm, D90后 =9.046μm, using the formula δ=(D90 前 -D90 后 )*100 / D90 前 The D90 mobility δ was calculated to be 45.1%.

[0104] Example 12

[0105] A method for testing the strength of diamond coarse abrasive grains, the specific steps are as follows:

[0106] ① Place the diamond sample in an oven and dry it at 110°C for 3 hours, and use the sieving method to obtain the basic particles of the diamond coarse abrasive sample.

[0107] ②Install the PCD lower indenter into the PCD cavity, then load 0.4g of the 20 / 25 mesh diamond coarse abrasive (Type 2 material) sample in step ① into the PCD cavity, install the PCD upper indenter, and apply pressure at both ends of the PCD upper and lower indenters to compact the diamond sample.

[0108] ③ Turn on the ultrasonic system, set the ultrasonic power to 1000W, the vibration frequency to 20KHz, and the ultrasonic vibration time to 3min, so that the diamond can vibrate under the action of ultrasound to achieve collision and wear between particles.

[0109] ④ The diamond sample after ultrasonic crushing in step ③ is taken out from the tank, and the basic particle mass of the diamond sample after ultrasonic crushing is obtained by screening method, which is 0.3995g.

[0110] In this embodiment, the diamond abrasive grain m 0 =0.4g,m 1 =0.3995g, using the formula φ=(m 0 -m 1 )*100 / m 0 Calculation is performed, φ=12.5%.

[0111] Example 13

[0112] A method for testing the strength of diamond coarse abrasive grains, the specific steps are as follows:

[0113] ① Place the diamond sample in an oven and dry it at 105°C for 5 hours, and use the sieving method to obtain the basic particles of the diamond coarse abrasive sample.

[0114] ②Insert the PCD lower indenter into the PCD cavity, then load 0.5g of the 35 / 40 mesh diamond coarse abrasive grain (Type 2 material) sample in step ① into the PCD cavity, install the PCD upper indenter, and apply pressure at both ends of the PCD upper and lower indenters to compact the diamond sample.

[0115] ③ Turn on the ultrasonic system, set the ultrasonic power to 2000W, the vibration frequency to 40KHz, and the ultrasonic vibration time to 8min, so that the diamond can vibrate under the action of ultrasound to achieve collision and wear between particles.

[0116] ④ The diamond sample after ultrasonic crushing in step ③ is taken out from the tank, and the basic particle mass of the diamond sample after ultrasonic crushing is obtained by screening method, which is 0.49775g.

[0117] In this embodiment, the diamond abrasive grain m 0 =0.5g, m 1 =0.49775g, using the formula φ=(m 0 -m 1 )*100 / m 0 Calculation is performed, φ=45%.

[0118] Embodiment 14

[0119] A method for testing the strength of diamond coarse abrasive grains, the specific steps are as follows:

[0120] ① Place the diamond sample in an oven and dry it at 110°C for 3 hours, and use the sieving method to obtain the basic particles of the diamond coarse abrasive sample.

[0121] ②Install the PCD lower indenter into the PCD mold cavity, then load 1g of the 60 / 70 mesh diamond coarse abrasive (2.5 type material) sample in step ① into the PCD mold cavity, install the PCD upper indenter, and apply pressure at both ends of the PCD upper and lower indenters to compact the diamond sample.

[0122] ③ Turn on the ultrasonic system, set the ultrasonic power to 2000W, the vibration frequency to 20KHz, and the ultrasonic vibration time to 3min, so that the diamond can vibrate under the action of ultrasound to achieve collision and wear between particles.

[0123] ④ The diamond sample after ultrasonic crushing in step ③ is taken out from the tank, and the basic particle mass of the diamond sample after ultrasonic crushing is obtained by screening method, which is 0.99835g.

[0124] In this embodiment, the diamond abrasive grain m 0 =1g,m 1 =0.99835g, using the formula φ=(m 0 -m 1 )*100 / m 0 Calculation is performed, φ=16.5%.

[0125] Embodiment 15

[0126] A method for testing the strength of diamond coarse abrasive grains, the specific steps are as follows:

[0127] ① Place the diamond sample in an oven and dry it at 110°C for 3 hours, and use the sieving method to obtain the basic particles of the diamond coarse abrasive sample.

[0128] ②Install the PCD lower indenter into the PCD mold cavity, then load 0.6g of the 80 / 100 mesh diamond coarse abrasive (type 3 crushed material) sample in step ① into the PCD mold cavity, install the PCD upper indenter, and apply pressure at both ends of the PCD upper and lower indenters to compact the diamond sample.

[0129] ③ Turn on the ultrasonic system, set the ultrasonic power to 2000W, the vibration frequency to 20KHz, and the ultrasonic vibration time to 3min, so that the diamond can vibrate under the action of ultrasound to achieve collision and wear between particles.

[0130] ④ The diamond sample after ultrasonic crushing in step ③ is taken out from the tank, and the basic particle mass of the diamond sample after ultrasonic crushing is obtained by screening method, which is 0.5995g.

[0131] In this embodiment, the diamond abrasive grain m 0 =0.6g,m 1 =0.5995g, using the formula φ=(m 0 -m 1 )*100 / m 0 Calculation is performed, φ=8.3%.

[0132] Example 16

[0133] A method for testing the strength of diamond coarse abrasive grains, the specific steps are as follows:

[0134] ① Place the diamond sample in an oven and dry it at 110°C for 3 hours, and use the sieving method to obtain the basic particles of the diamond coarse abrasive sample.

[0135] ②Install the PCD lower indenter into the PCD cavity, then load 0.4g of the 140 / 170 mesh diamond coarse abrasive (Type 2 crushed material) sample in step ① into the PCD cavity, install the PCD upper indenter, and apply pressure at both ends of the PCD upper and lower indenters to compact the diamond sample.

[0136] ③ Turn on the ultrasonic system, set the ultrasonic power to 1000W, the vibration frequency to 40KHz, and the ultrasonic vibration time to 6min, so that the diamond can vibrate under the action of ultrasound to achieve collision and wear between particles.

[0137] ④ The diamond sample after ultrasonic crushing in step ③ is taken out from the tank, and the basic particle mass of the diamond sample after ultrasonic crushing is obtained by screening method, which is 0.39915g.

[0138] In this embodiment, the diamond abrasive grain m 0 =0.4g,m1 =0.39915g, using the formula φ=(m 0 -m 1 )*100 / m 0 Calculation is performed, φ=21.2%.

[0139] Embodiment 17

[0140] A method for testing the strength of diamond coarse abrasive grains, the specific steps are as follows:

[0141] ① Place the diamond sample in an oven and dry it at 110°C for 3 hours, and use the sieving method to obtain the basic particles of the diamond coarse abrasive sample.

[0142] ②Install the PCD lower indenter into the PCD mold cavity, then load 0.5g of the 200 / 230 mesh diamond coarse abrasive (1.5 type crushed material) sample in step ① into the PCD mold cavity, install the PCD upper indenter, and apply pressure at both ends of the PCD upper and lower indenters to compact the diamond sample.

[0143] ③ Turn on the ultrasonic system, set the ultrasonic power to 1000W, the vibration frequency to 40KHz, and the ultrasonic vibration time to 8min, so that the diamond can vibrate under the action of ultrasound to achieve collision and wear between particles.

[0144] ④ The diamond sample after ultrasonic crushing in step ③ is taken out from the tank, and the basic particle mass of the diamond sample after ultrasonic crushing is obtained by screening method, which is 0.49786g.

[0145] In this embodiment, the diamond abrasive grain m 0 =0.5g, m 1 =0.49786g, using the formula φ=(m 0 -m 1 )*100 / m 0 Calculation shows that φ=42.8%.

[0146] Embodiment 18

[0147] A method for testing the strength of diamond coarse abrasive grains, the specific steps are as follows:

[0148] ① Place the diamond sample in an oven and dry it at 110°C for 3 hours, and use the sieving method to obtain the basic particles of the diamond coarse abrasive sample.

[0149] ②Install the PCD lower indenter into the PCD cavity, then load 0.4g of the 270 / 325 mesh diamond coarse abrasive (Type 1 crushed material) sample in step ① into the PCD cavity, install the PCD upper indenter, and apply pressure at both ends of the PCD upper and lower indenters to compact the diamond sample.

[0150] ③ Turn on the ultrasonic system, set the ultrasonic power to 2000W, the vibration frequency to 40KHz, and the ultrasonic vibration time to 8min, so that the diamond can vibrate under the action of ultrasound to achieve collision and wear between particles.

[0151] ④ The diamond sample after ultrasonic crushing in step ③ is taken out from the tank, and the basic particle mass of the diamond sample after ultrasonic crushing is obtained by screening method, which is 0.39802g.

[0152] In this embodiment, the diamond abrasive grain m 0 =0.4g,m 1 =0.39802g, using the formula φ=(m 0 -m 1 )*100 / m 0 Calculation is performed, φ=49.5%.

[0153] Embodiment 19

[0154] A method for testing the strength of diamond coarse abrasive grains, the specific steps are as follows:

[0155] ① Place the diamond sample in an oven and dry it at 110°C for 3 hours, and use the sieving method to obtain the basic particles of the diamond coarse abrasive sample.

[0156] ②Install the PCD lower indenter into the PCD cavity, then load 0.6g of the 325 / 400 mesh diamond coarse abrasive (Type 2 crushed material) sample in step ① into the PCD cavity, install the PCD upper indenter, and apply pressure at both ends of the PCD upper and lower indenters to compact the diamond sample.

[0157] ③ Turn on the ultrasonic system, set the ultrasonic power to 2000W, the vibration frequency to 30KHz, and the ultrasonic vibration time to 8min, so that the diamond can vibrate under the action of ultrasound to achieve collision and wear between particles.

[0158] ④ The diamond sample after ultrasonic crushing in step ③ is taken out from the tank, and the basic particle mass of the diamond sample after ultrasonic crushing is obtained by screening method, which is 0.59785g.

[0159] In this embodiment, the diamond abrasive grain m 0 =0.6g,m 1 =0.59785g, using the formula φ=(m 0 -m 1 )*100 / m 0 Calculation is performed, φ=35.8%.

[0160] The above is a detailed introduction to a diamond strength testing device and method provided by the present invention. This article uses specific examples to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method and core ideas of the present invention. It should be pointed out that for ordinary technicians in this technical field, without departing from the principles of the present invention, the present invention can also be improved and modified in a number of ways, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

Claims

1. A diamond strength testing method, It is characterized in that The diamond strength testing method adopts a testing device comprising a PCD mold cavity (1) and an ultrasonic vibration source (4, 4'); a PCD upper pressure head (2) is located in the PCD mold cavity (1) and its upper end is fixed on the ultrasonic vibration source (4); a PCD lower pressure head (3) is located in the PCD mold cavity (1) and its lower end is fixed on the ultrasonic vibration source (4'); the PCD mold cavity (1), the PCD upper pressure head (2) and the PCD lower pressure head (3) form a closed structure; The specific steps are as follows: ①Put the diamond sample in an oven for drying; ②Insert the PCD lower indenter into the PCD mold cavity, then install the diamond sample dried in step ① into the PCD mold cavity, install the PCD upper indenter, and apply pressure at both ends of the PCD upper indenter and the PCD lower indenter to compact the diamond sample; ③ Turn on the ultrasonic system to make the diamond sample vibrate under the action of ultrasound to achieve collision and wear between particles, and obtain the diamond sample after ultrasonic crushing; ④ Carry out strength test and evaluation on the diamond sample after ultrasonic crushing in step ③; The ultrasonic output power is 1000-2000W, the ultrasonic frequency is 20-40KHz, and the ultrasonic time is 1-8min; In step ④, when the diamond sample is diamond coarse abrasive grains, the diamond coarse abrasive grains have a particle size of 16 / 18 to 325 / 400 meshes; the diamond coarse abrasive grains are tested by screening method to detect the mass change rate φ of the basic grains before and after ultrasonic crushing to evaluate their strength, φ=(m 0 -m 1 )*100 / m 0 ; the φ is negatively correlated with the strength value of the diamond coarse abrasive grains, and the higher the φ value, the lower the strength value of the diamond coarse abrasive grains; Or in step ④, when the diamond sample is diamond powder, the particle size of the diamond powder is ≤36 / 54μm; the diamond powder is evaluated for its strength by the mobility δ of D90 before and after ultrasonic crushing; the D90 is the particle size corresponding to 90% of the cumulative volume fraction of the particles when detected by a laser particle size analyzer, δ=(D90 before-D90 after)*100 / D90 before; the δ value is negatively correlated with the diamond strength value, and the higher the δ value, the lower the strength value of the diamond powder.

2. The diamond strength testing method according to claim 1, Features: In step ①, the diamond sample is dried at a temperature of 105-115° C. and for a drying time of 2-4 hours.

3. The diamond strength testing method according to claim 1, Features: In step ②, the mass of the diamond sample in the PCD cavity is 0.3-2.0 g.

4. The diamond strength testing method according to claim 1, Features: In step ②, after the diamond sample is compacted, the PCD upper indenter and the PCD lower indenter cannot move relative to each other.

Images