Equivalent test method for semi-fracture time of piston and rocker arm impactor

Abstract

This invention relates to an equivalent testing method for the semi-crushing time of piston and rocker arm impact testers, belonging to the technical field of impact toughness testing for superhard abrasives. This invention solves the global technical challenge of inconsistent test results for the same sample using piston and rocker arm impact testers in semi-crushing time methods. It enables the world's most widely used semi-crushing time testing method to achieve identical test results for the same superhard abrasive sample using piston and rocker arm impact testers, which are completely different in working principle and structure. This unifies the test results for users of different impact equipment, avoiding conflicts and disputes in international trade of superhard abrasives caused by inconsistent test results, and also preventing economic losses and waste resulting from replacing one impact tester with another.

Description

Technical Field

[0001] This invention belongs to the field of superhard abrasive impact toughness testing technology, specifically relating to an equivalent testing method for the semi-fracture time of a piston and rocker arm impactor. Background Technology

[0002] Piston impact testers and rocker arm impact testers are important equipment for testing the impact toughness of superhard abrasives. Superhard abrasives mainly refer to abrasives with very high hardness, such as diamond and cubic boron nitride, primarily used in cutting tools and grinding wheels; superhard abrasives are a core element of these tools. A key performance indicator of superhard abrasives is impact toughness. Globally, there are two main methods for testing impact toughness: the semi-fracture time test method and the non-fracture rate test method. The expression indicators (evaluation indicators) and calculation formulas of these two methods are completely different. The semi-fracture time test method uses the length of time or the number of impact cycles (time can be converted to impact cycles) to express the impact toughness of superhard abrasives. The non-fracture rate test method uses the proportion of unfractured material in the total sample to express the impact toughness of superhard abrasives. The computational complexity of the two test methods also differs greatly, each with its own significant advantages. Compared to the non-fracture rate test method, the calculation formula and testing procedures of the semi-fracture time test method are much more complex. Both test methods can be performed using piston impact testers or rocker arm impact testers.

[0003] As mentioned above, there are two main types of impact equipment used in the semi-fracture time test and the non-fracture rate test: a piston impactor and a rocker arm impactor. The design principles and structures of these two types of impact equipment are completely different. The piston impactor uses an impact tube containing superhard abrasive material to impact the abrasive material through the reciprocating motion of a piston. The piston impactor consists of an impact tube 1, an impact tube frame 2, a connecting rod 3, a drive wheel 4, a motor shaft 5, and a piston 6, etc., and its structure is shown in [the diagram]. Figure 1 As shown. The rocker arm impactor uses a reciprocating motion of an impact tube containing superhard abrasive to impact the abrasive. The rocker arm impactor consists of an impact tube 1, an impact tube frame 2, a connecting rod 3, a drive wheel 4, a motor shaft 5, a rocker arm 6', and a rocker arm shaft 7, etc., and its structure is shown in [the diagram]. Figure 2 As shown. Both rocker arm vibrators and piston vibrators have their advantages and disadvantages. Rocker arm vibrators have the advantages of high impact frequency and long operating time, making them suitable for production inspection, but they are large and heavy. Piston vibrators, on the other hand, have the advantages of small size and light weight, but they are prone to overheating and cannot operate for extended periods, making them suitable for precision testing and arbitration testing.

[0004] The distribution of the two testing methods and the two types of impact instruments varies greatly around the world. The United States, Europe, and Japan mainly use the semi-fracture time test method, while China mainly uses the non-fracture rate test method. The United States, Japan, and China mostly use rocker arm impactors and a small number use piston impactors, while European countries mostly use piston impactors and a small number use rocker arm impactors.

[0005] When two different devices test the same superhard abrasive sample using the same testing method (semi-crushing time method or non-crushing rate method), the results obtained are completely different. This makes it impossible for superhard abrasive manufacturers and users in different regions of the world to uniformly evaluate the same abrasive performance, seriously affecting the unified evaluation of superhard abrasive performance and the development of international trade.

[0006] The most intuitive approach to unification is to unify the two methods into one and the two types of equipment into one. However, since the two testing methods each have their own significant advantages and have established usage habits among users worldwide, unifying the testing methods is impossible. Similarly, the two impact testing devices for superhard abrasives also have their own performance advantages. Furthermore, users of various impact testers have invested heavily in purchasing their equipment and are accustomed to using their own devices; therefore, replacing one impact tester with another to achieve equipment unification is also impossible. Thus, the problem of unifying test results for the same superhard abrasive sample using two different types of testing equipment for one testing method can only be solved through technical means. When using the non-fracture rate testing method, the equivalent testing method for testing the same sample using a piston impactor and a rocker arm impactor has been solved by the authorized patent (patent number: ZL 202011497349.2) "Equivalent Testing Method for Rocker Arm and Piston Vibrators". However, the equivalent testing method for the same sample using a piston impactor and a rocker arm impactor for the semi-fracture time testing method is too technically complex, and a technical solution for testing equivalence has not yet been found. The semi-fracture time test method is the most widely used method in the world, and many countries and companies use this test method with piston impactors and rocker arm impactors.

[0007] For the same superhard abrasive sample, the results of testing with a piston impact tester and a rocker arm impact tester using the same semi-crushing time method can differ significantly. For example, for a high-grade sample with a size of D426, the result of the piston impact test is 260s, while the result of the rocker arm impact test is 150s. The same test method and the same sample yield different results due to the use of different impact equipment. This makes it impossible to uniformly assess the performance level of superhard abrasives among manufacturers and users (such as cutting tool manufacturers) worldwide, who possess different types of testing equipment. The performance indicators provided by different superhard abrasive manufacturers are not comparable due to the use of different types of testing equipment. Different superhard abrasive users also cannot confirm the performance level of the supplied abrasives due to inconsistencies in equipment compared to the manufacturers. A long semi-crushing time provided by the manufacturer does not necessarily indicate high performance, and a short semi-crushing time tested by the user does not necessarily indicate low performance. This inconsistency in test results has resulted in a lack of standardized performance indicators for the procurement and delivery of superhard abrasive products, severely impacting both domestic and international trade and leading to numerous trade disputes. Ensuring the equivalence or standardization of semi-fracture time testing results using these two different impact testers, while maintaining the two widely used types in various countries, has become a pressing global technical challenge in the field of superhard abrasives. Summary of the Invention

[0008] (a) Technical problems to be solved

[0009] The technical problem this invention aims to solve is to create a method for achieving equivalent test results using the semi-fracture time method with piston impactors and rocker arm impactors. This method ensures that the test results of the most widely used semi-fracture time test method worldwide are consistent when testing the same sample with two different impactors. It avoids the waste of equipment investment and learning costs associated with replacing one impactor with another to achieve uniform test results. The goal is to ensure that the test results of the semi-fracture time method are comparable and consistent worldwide, regardless of whether a piston impactor or a rocker arm impactor is used.

[0010] (II) Technical Solution

[0011] To address the aforementioned technical problems, this invention provides an equivalent testing method for the semi-fracture time of a piston and rocker arm impactor, comprising the following steps:

[0012] S1. Select specification size as S i The samples include high-grade, medium-grade, and low-grade samples, where i represents the grade of superhard abrasive. At least four batches of samples should be prepared for each grade.

[0013] S2. Set the standard vibration frequency f of the rocker arm impact tester respectively. r The standard vibration frequency f of the piston impactor p ;

[0014] S3, for specifications and dimensions S i For the samples, the impact time t for high, medium and low grade samples to be impacted by a rocker arm impactor with a non-breakage rate in the range of 45% to 50% was estimated. rH1 , t rM1 and t rL1 In addition, the impact time t for high, medium and low grade samples to be impacted by a piston impactor when the sample non-breakage rate is in the range of 45% to 50% was estimated. pH1 , t pM1 and t pL1 ;

[0015] S4. Apply the estimated impact time t of the corresponding high-grade sample to each rocker arm and piston impactor. rH1 and t pH1 Set the impact time; place a high-grade sample into the impact tube of each impactor, then install the impact tube onto the impactor and start each impactor to perform the impact operation.

[0016] S5. The impacted samples are sieved and weighed to obtain the impact time T for the rocker arm impactor. rH1 Impact failure rate P rH1 The piston impactor uses the impact time T. pH1 Impact failure rate P pH1 P rH1 and P pH1 The unbroken rate is between 45% and 50%.

[0017] S6. When the unbroken rate of a sample impacted by a rocker arm impactor or piston impactor is less than 45%, appropriately reduce the impact time of the corresponding sample, and perform the same impact with a new, identical sample until the unbroken rate of the sample is between 45% and 50%. At this point, record the impact time T of the rocker arm impactor. rH1 and the non-fracture rate P of its impact specimen rH1 Impact time T of the piston impactor pH1 and the non-fracture rate P of its impact specimen pH1 ;

[0018] S7. Following S4 to S6, estimate the impact time t using two types of impact testers for medium-grade and low-grade samples, respectively. rM1 With t pM1 and t rL1 With t pL1The sample was impacted using a suitable impactor, then sieved and weighed to obtain the impact time T of the rocker arm impactor on the medium-grade sample. rM1 And the unbroken rate P of the sample rM1 The impact time T of the piston impactor on the medium-grade sample pM1 And the unbroken rate P of the sample pM1 And the impact time T of the rocker arm impactor on the low-grade sample. rL1 And the unbroken rate P of the sample rL1 The impact time T of the piston impactor on the low-grade sample pL1 And the unbroken rate P of the sample pL1 ;

[0019] S8. Following steps S1 to S7, conduct impact tests on high-grade, medium-grade, and low-grade samples using a rocker arm impactor and a piston impactor, respectively. The non-breakage rate of the samples after impact should be between 50% and 55%. When the non-breakage rate of a sample impacted by the rocker arm impactor or piston impactor exceeds 55%, appropriately increase the impact time of the corresponding sample and perform the same impact with a new, identical sample until the non-breakage rate of the sample is between 50% and 55%. At this point, record the impact time T of the rocker arm impactor on the samples of the three grades. rH2 T rM2 and T rL2 and the corresponding non-fracture rate P of the impact specimen rH2 P rM2 and P rL2 The impact time T of the piston impactor on the three grades of samples. pH2 T pM2 and T pL2 and the non-fracture rate P of its impact specimen pH2 P pM2 and P pL2 ;

[0020] S9. Using formulas (1), (2), and (3), calculate the impact time T for high-grade, medium-grade, and low-grade samples when the breakage rate is 50%, respectively, using a rocker arm impactor. rH50 T rM50 and T rL50 This is then further converted into the corresponding number of impact cycles C. rH50 C rM50 and C rL50 :

[0021]

[0022]

[0023]

[0024] S10. Using formulas (4), (5), and (6), calculate the impact time T for high-grade, medium-grade, and low-grade samples when the non-breakage rate is 50%, respectively, using a piston impactor. pH50 T pM50 and T pL50 This is then further converted into the corresponding number of impact cycles C. pH50 C pM50 and C pL50 :

[0025]

[0026]

[0027]

[0028] S11. Using formulas (7), (8), and (9), calculate the number of impact cycles C of the piston impact tester for the three grades of samples. pH50 C pM50 and C pL50 The number of impact cycles C of the rocker arm impact tester applied to the corresponding grade of sample. rH50 C rM50 and C rL50 R H50 R M50 and R L50 :

[0029]

[0030]

[0031]

[0032] S12. Using formula (10), calculate the impact cycle ratio R of the three grades of samples. H50 R M50 and R L50 The average value r A50 :

[0033]

[0034] S13. Following steps S1 to S12, repeat the parallel tests using the same sample grade and batch number as in steps S1 to S12. Take the average of the two parallel tests as the result R. A50 ;

[0035] S14, Calculate R A50 Reduce R H50 R M50 Or R L50 One divided by R A50We obtain three relative percentages. When any one of the three relative percentages is not greater than 1.5%, [|R] A50 -R x50 | / R A50 =R D50max / R A50 ]≦1.5%, x=H, M or L; R D50max =|R A50 -R x50 | Execute step S15; when any of the three relative percentages is greater than 1.5%, execute step S16; when the three relative percentages are much greater than 1.5%, that is, when the preset threshold is reached or exceeded, and the expected accuracy is greater than the preset value of the equivalent test result, execute step S17.

[0036] S15. At this point, the equivalent test results C of each grade sample impacted by a piston impactor or rocker arm impactor. Epx50 Or C Erx50 The calculation does not consider the relative percentage grade relationship when a sample size specification S is used. i The impact test result of any new sample of any grade subjected to impact testing using a rocker arm impact tester or a piston impact tester is C. Nrx50 Or C Npx50 The equivalent test result C of impacting the same sample with a piston impactor or rocker arm impactor different from the previous impactor. Epx50 Or C Erx50 Calculate using formula (11) or formula (12) respectively:

[0037] C Epx50 =R A50 ·C Nrx50 (11)

[0038]

[0039] S16. At this point, if any one of the three relative percentages is greater than 1.5%, [|R A50 -R x50 | / R A50 =R D50max / R A50 >1.5%, equivalent test results C of each grade of sample using a piston impact tester or rocker arm impact tester. Epx50 Or C Erx50 The calculation considers the relative percentage grade relationship. In this case, the equivalent test result of the piston impactor or rocker arm impactor for high-grade samples is C. EpH50 Or C ErH50 The equivalent test result for the medium-grade sample is C. EpM50 Or C ErM50 The equivalent test result for the low-grade sample is C. EpL50Or C ErL50 When in a sample size specification S i New samples of medium-high grade, medium grade, and low grade were subjected to impact testing using a rocker arm impact tester or a piston impact tester. The corresponding test result for high-grade samples was C. NrH50 Or C NpH50 The medium grade is C. NrM50 Or C NpM50 The lower grade is C. NrL50 Or C NpL50 Equivalent test results C of three grades of the same sample tested using a piston impactor or rocker arm impactor different from the previous impactor. EpH50 Or C ErH50 C EpM50 Or C ErM50 C EpL50 Or C ErL50 Calculate using formulas (13), (14), (15), (16), (17), or (18) respectively:

[0040] C EpH50 =R H50 ·C NrH50 (13)

[0041]

[0042] C EpM50 =R M50 ·C NrM50 (15)

[0043]

[0044] C EpL50 =R L50 ·C NrL50 (17)

[0045]

[0046] S17. At this point, the three relative percentages are much greater than 1.5%, and the expected accuracy is greater than the preset value. For the equivalent test results, the number of grade layers of the test sample of the same size is increased to 5 or 7 grades. In this case, referring to steps S1 to S16, the equivalent calculation formula for 5 or 7 grades of samples in one size is reconstructed, and then these formulas are applied to calculate the equivalent test results between the rocker arm impactor and the piston impactor.

[0047] Preferably, after step S17, the method further includes: step S18, converting the equivalent number of impact cycles of the three grades of piston impactor and rocker arm impactor into equivalent impact time according to formulas (19) and (20):

[0048] TEpx50 =C Epx50 ×f p (19)

[0049] T Erx50 =C Erx50 ×f r (20)

[0050] This allows us to obtain equivalent test results for samples of different grades of superhard abrasives of the same size when tested using a piston impact tester and a rocker arm impact tester.

[0051] Preferably, after step S18, step S19 is also included: obtaining equivalent test results of samples of each grade in all sizes of superhard abrasives tested between a piston impact tester and a rocker arm impact tester.

[0052] The present invention also provides a system for implementing the method.

[0053] The present invention also provides an application of the method in the field of impact toughness testing technology for superhard abrasives.

[0054] The present invention also provides an application of the system in the field of superhard abrasive impact toughness testing technology.

[0055] (III) Beneficial Effects

[0056] This invention uses high-grade, medium-grade, and low-grade samples of superhard abrasives of the same size as the comparison objects for the equivalent relationship between two types of impact testers. A semi-fracture time method is used to obtain the time required for a 50% non-fracture rate of the sample by impacting the same sample with both piston and rocker arm impact testers, and this time is converted into impact cycles. The ratio of the semi-fracture impact cycles of the same grade samples by piston and rocker arm impact testers is calculated to obtain the difference in the impulse ratio of the two types of impact testers on the three grade samples. The deviation range of the relative percentage of the impact cycle ratio or the linearity of the impact cycle ratio between the samples of each grade is determined to decide the calculation scheme of the equivalent test results. The equivalent test results of the two types of impact testers are calculated according to the formula corresponding to the relative percentage deviation range. For samples of certain sizes with severe nonlinearity, the number of grade divisions is increased to achieve high-precision equivalence between the two types of impact testers. Based on the needs of using the test results, the equivalent impact cycles are converted into equivalent impact time. Based on the above technical solutions, this invention solves the global technical challenge of inconsistent test results for the same sample using piston impactors and rocker arm impactors in the semi-fracture time method. It enables the world's most widely used semi-fracture time testing method to achieve identical test results for the same superhard abrasive sample using piston impactors and rocker arm impactors, which are completely different in working principle and structure. This unifies the test results for users of different impact equipment, avoiding conflicts and disputes in international trade of superhard abrasives caused by inconsistent test results, and also avoiding the economic losses and waste resulting from replacing one impact testing instrument with another. This equivalent method also has the advantage that the equivalent of a sample tested on one impact testing instrument can be obtained simply through calculation for another impact testing instrument, saving the costs of labor, time, sample and equipment wear associated with testing on another impact testing instrument. The unification of test results from different testing equipment in this invention will promote the development of international trade, facilitate academic exchange in the field of superhard abrasives, and establish a favorable environment for international quality assessment of superhard abrasives. Attached Figure Description

[0057] Figure 1 This is a structural diagram of a piston impactor;

[0058] Figure 2 This is a structural diagram of a rocker arm impactor;

[0059] Figure 3 This is a graph showing the relationship between the relative percentage of impact cycles in this invention and a value not exceeding 1.5%.

[0060] Figure 4 This is a graph showing the relationship between the relative percentage of impact cycles greater than 1.5% in this invention;

[0061] Figure 5 This is a graph showing the relationship between the relative percentage of impact cycles in this invention and a percentage that is much greater than 1.5%. Detailed Implementation

[0062] To make the objectives, contents, and advantages of the present invention clearer, the specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples.

[0063] The inventors of this invention discovered that, for samples of the same particle size in three grades—high, medium, and low—the semi-crushing impact cycles corresponding to the semi-crushing time are measured using a piston impactor and a rocker arm impactor respectively, using the semi-crushing time test method. The ratio of the corresponding semi-crushing impact cycles of the three grades of samples measured by the piston impactor and rocker arm impactor is calculated, the average value of the semi-crushing impact cycle ratio of the three grades of samples is calculated, the relative percentage of the semi-crushing impact cycle ratio is calculated, and a deviation limit value for the relative percentage of the semi-crushing impact cycle ratio is set (e.g., 1.5% or 2%). By comparing the relative percentage of the semi-crushing impact cycle ratio of the three grades of the test sample with the deviation limit value, the linearity of the impulse ratio of the piston impactor and rocker arm impactor on the tested sample of the three grades can be evaluated. Further, based on the linearity of the impulse ratio, the type of formula used for equivalent calculation is determined. For impulse ratios with good linearity, the average of the relative percentages of the semi-fracture impact cycle ratio is used to calculate the equivalent test value. For impulse ratios with poor linearity, the relative percentages of the semi-fracture impact cycle ratios of the three grades of samples are used to calculate the equivalent test value. This allows us to obtain the equivalent test results of each grade of superhard abrasive of the same size tested between the piston impact tester and the rocker arm impact tester.

[0064] Based on the above inventive concept, the equivalent testing method of the present invention specifically includes the following steps:

[0065] S1. Select specification size as S i (i represents the grade of superhard abrasive, i = D851,…,D46,B301,…,B46, for example S) D426 =40 / 45, its grade is D426) The samples are high grade, medium grade and low grade. Prepare at least 4 batches or more of the samples for each grade (3×4=12 batches or more for the three grades).

[0066] S2. Select and set the standard vibration frequency f of the rocker arm impactor respectively. r The standard vibration frequency f of the piston impactor p For example, f r =2400r / min,f p =1420r / min.

[0067] S3, for specifications and dimensions S iFor the samples, the impact time t for high, medium and low grade samples to be impacted by a rocker arm impactor with a non-breakage rate in the range of 45% to 50% was estimated. rH1 , t rM1 and t rL1 In addition, the impact time t for high, medium, and low grade samples to be impacted by a piston impactor with a breakage rate in the range of 45% to 50% was estimated. pH1 , t pM1 and t pL1 .

[0068] S4. Apply the estimated impact time t of the corresponding high-grade sample to each rocker arm and piston impactor. rH1 and t pH1 Set the impact time. Place a high-grade sample into the impact tube of each impactor, then install the impact tube onto the impactor and start each impactor to perform the impact operation.

[0069] S5. The impacted samples are sieved and weighed to obtain the impact time T for the rocker arm impactor. rH1 Impact failure rate P rH1 The piston impactor uses the impact time T. pH1 Impact failure rate P pH1 (P rH1 and P pH1 The unbroken rate is between 45% and 50%.

[0070] S6. When the breakage rate of samples impacted by the rocker arm impactor or piston impactor is less than 45%, appropriately reduce the impact time of the corresponding samples, and perform the same impact with new, identical samples until the breakage rate of the samples is between 45% and 50%. At this point, record the impact time T of the rocker arm impactor. rH1 and the non-fracture rate P of its impact specimen rH1 Impact time T of the piston impactor pH1 and the non-fracture rate P of its impact specimen pH1 .

[0071] S7. Following S4 to S6, estimate the impact time t using two types of impact testers for medium-grade and low-grade samples, respectively. rM1 With t pM1 and t rL1 With t pL1 The sample was impacted using a suitable impactor, then sieved and weighed to obtain the impact time T of the rocker arm impactor on the medium-grade sample. rM1 And the unbroken rate P of the sample rM1 The impact time T of the piston impactor on the medium-grade sample pM1 And the unbroken rate P of the sample pM1And the impact time T of the rocker arm impactor on the low-grade sample. rL1 And the unbroken rate P of the sample rL1 The impact time T of the piston impactor on the low-grade sample pL1 And the unbroken rate P of the sample pL1 .

[0072] S8. Following S1 to S7, conduct impact tests on high-grade, medium-grade, and low-grade samples using a rocker arm impact tester and a piston impact tester, respectively. The non-breakage rate of the samples after impact should be between 50% and 55% for all three grades. When the non-breakage rate of any sample impacted by the rocker arm impact tester or piston impact tester exceeds 55%, appropriately increase the impact time of the corresponding sample, and perform the same impact test with a new, identical sample until the non-breakage rate of the sample is between 50% and 55%. At this point, record the impact time T of the rocker arm impact tester on the samples of the three grades. rH2 T rM2 and T rL2 and the corresponding non-fracture rate P of the impact specimen rH2 P rM2 and P rL2 The impact time T of the piston impactor on the three grades of samples. pH2 T pM2 and T pL2 and the non-fracture rate P of its impact specimen pH2 P pM2 and P pL2 .

[0073] S9. Using formulas (1), (2), and (3), calculate the impact time T for high-grade, medium-grade, and low-grade samples when the breakage rate is 50%, respectively, using a rocker arm impactor. rH50 T rM50 and T rL50 This is then further converted into the corresponding number of impact cycles C. rH50 C rM50 and C rL50 .

[0074]

[0075]

[0076]

[0077] S10. Using formulas (4), (5), and (6), calculate the impact time T for high-grade, medium-grade, and low-grade samples when the non-breakage rate is 50%, respectively, using a piston impactor. pH50 T pM50 and T pL50 This is then further converted into the corresponding number of impact cycles C.pH50 C pM50 and C pL50 .

[0078]

[0079]

[0080]

[0081] S11. Using formulas (7), (8), and (9), calculate the number of impact cycles C of the piston impact tester for the three grades of samples. pH50 C pM50 and C pL50 The number of impact cycles C of the rocker arm impact tester applied to the corresponding grade of sample. rH50 C rM50 and C rL50 R H50 R M50 and R L50 .

[0082]

[0083]

[0084]

[0085] S12. Using formula (10), calculate the impact cycle ratio R of the three grades of samples. H50 R M50 and R L50 The average value r A50 .

[0086]

[0087] S13. Following S1 to S12, repeat the parallel tests using the same sample grade and batch number as in S1 to S12. Take the average of the two parallel tests as the result R. A50 .

[0088] S14, Calculate R A50 Reduce R H50 R M50 Or R L50 One divided by R A50 We obtain three relative percentages, {for example, the relative percentage of impact cycles for high-grade samples is obtained using the formula [(R A50 -R H50 ) / R A50 ] indicates that when any of the three relative percentages is not greater than 1.5%, {[|R A50 -Rx50 | / R A50 =R D50max / R A50 ]≦1.5%, x=H, M or L; R D50max =|R A50 -R x50 |}, see Figure 3 As shown, proceed to step S15; when any one of the three relative percentages is greater than 1.5%, proceed to step S16; when the three relative percentages are much greater than 1.5%, reaching and exceeding 3.0%, and a high-precision equivalent test result is desired, proceed to step S17.

[0089] S15. At this point, the equivalent test results C of each grade sample impacted by a piston impactor or rocker arm impactor. Epx50 Or C Erx50 The calculation does not require consideration of relative percentage grade relationships. When in a sample size specification S i The impact test result of any new sample of any grade subjected to impact testing using a rocker arm impact tester or a piston impact tester is C. Nrx50 Or C Npx50 The equivalent test result C of impacting the same sample with a piston impactor or rocker arm impactor different from the previous impactor. Epx50 Or C Erx50 Calculate according to formula (11) or formula (12) respectively.

[0090] C Epx50 =R A50 ·C Nrx50 (11)

[0091]

[0092] S16. At this point, any one of the three relative percentages is greater than 1.5% {[|R A50 -R x50 | / R A50 =R D50max / R A50 >1.5%, x = H, M or L; R D50max =|R A50 -R x50 |}, see Figure 4 As shown, the equivalent test results C of each grade of sample using a piston impact tester or a rocker arm impact tester are presented. Epx50 Or C Erx50 The calculation needs to consider the relative percentage grade relationship. In this case, the equivalent test result of the piston impactor or rocker arm impactor for high-grade samples is C. EpH50 Or C ErH50 The equivalent test result for the medium-grade sample is C. EpM50 Or CErM50 The equivalent test result for the low-grade sample is C. EpL50 Or C ErL50 When in a sample size specification S i New samples of medium-high grade, medium grade, and low grade were subjected to impact testing using a rocker arm impact tester or a piston impact tester. The corresponding test result for high-grade samples was C. NrH50 Or C NpH50 The medium grade is C. NrM50 Or C NpM50 The lower grade is C. NrL50 Or C NpL50 Equivalent test results C of three grades of the same sample tested using a piston impactor or rocker arm impactor different from the previous impactor. EpH50 Or C ErH50 C EpM50 Or C ErM50 C EpL50 Or C ErL50 Calculate according to formula (13), formula (14), formula (15), formula (16), formula (17) or formula (18) respectively.

[0093] C EpH50 =R H50 ·C NrH50 (13)

[0094]

[0095] C EpM50 =R M50 ·C NrM50 (15)

[0096]

[0097] C EpL50 =R L50 ·C NrL50 (17)

[0098]

[0099] S17. At this point, the three relative percentages are much greater than 1.5%, and high-precision equivalent test results are desired. Therefore, the number of grade layers for test samples of the same size should be increased to 5 or 7 grades, etc. See [reference needed]. Figure 5 As shown. In this case of severe nonlinear relative percentage, referring to S1 to S16, a high-precision equivalent calculation formula for 5 or 7 grades of samples in one size is reconstructed, and then these formulas are applied to calculate the equivalent test results between the rocker arm impactor and the piston impactor.

[0100] S18, relevant parameters for equivalent testing between piston impact testers and rocker arm impact testers (e.g., C)rH50 C rM50 C rL50 C pH50 C pM50 C pL50 R A50 R H50 R M50 R L50 Once established, for a given sample size, the equivalent test result of a new sample tested with one impactor against another impactor can be obtained by calculation, without the need for actual measurement. In this equivalent test method, the equivalent test result of the number of impact cycles can be converted into the equivalent test time, and the two can be converted to each other. The equivalent number of impact cycles for the three grades of piston impactor and rocker arm impactor is converted into the equivalent impact time according to formulas (19) and (20).

[0101] T Epx50 =C Epx50 ×f p (19)

[0102] T Erx50 =C Erx50 ×f r (20)

[0103] The equivalent test method established using the semi-fracture time test method can be used to obtain equivalent test results of samples of different grades of superhard abrasives of the same size between the piston impact tester and the rocker arm impact tester.

[0104] S19. Obtain equivalent test results for all grades of superhard abrasives of all sizes, tested using both piston impact testers and rocker arm impact testers. When testing all sizes of S... D851 ~S D46 and S B301 ~S B46 Once the relevant parameters for equivalent testing between the piston impactor and the rocker arm impactor are established, this testing method will be universally applicable to equivalent testing of superhard abrasives of various sizes.

[0105] The testing method of this invention was verified through actual testing experiments. The test data is shown in Table 1. The tests verified that the invention is very effective. The tests used diamond samples with a size of D426, each weighing 0.4g. The test samples were of three grades: high, medium, and low. The semi-fracture time method was used to test and measure the semi-fracture time and number of semi-fracture cycles for the three grades of samples using a piston impactor and a rocker arm impactor, respectively. The impact cycle ratio R of the three grades of samples was calculated. x50 Average number of weeks R A50The relative percentage of impact cycles. Since the relative percentages of the three grades of samples are 0.0%, -2.9%, and 1.9% respectively, and two of the three values ​​are greater than 1.5%, the formula for the equivalent test of the two impactors should be calculated by grade. Some samples of the high, medium, and low grades of D426 size were newly taken and tested using a rocker arm impactor and a piston impactor respectively using the semi-crushing time method. The test results of the rocker arm impactor were calculated using the algorithm of the invention to obtain the equivalent test results of the piston impactor. Then, the equivalent test results of the piston impactor were subtracted from the results of the actual test of the piston impactor (C). Epx50 -C Npx50 The calculated equivalent difference is very small compared with the measured difference. The differences for the three grades are -62(r), 8(r) and 49(r), respectively, which are -0.9%, 0.1% and 0.9% of the measured values, respectively. These are significantly less than the requirement of 1.5% for test accuracy (comparing absolute values ​​regardless of positive or negative numbers).

[0106] Table 1. Verification Tests of Equivalent Test Methods for the Semi-Fracturing Time Method using Piston Impact Tester and Rocker Arm Impact Tester

[0107]

[0108]

[0109] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method of equivalent testing of the piston and rocker arm impactor semi-break time, characterized in that, Includes the following steps: S1, selecting a size three grades of samples in the sample, high grade, medium grade and low grade, i representing the grade of superhard abrasive, at least 4 batches of samples are prepared for each grade of sample; S2. Set the standard vibration frequency of the rocker arm impactor respectively. and the standard vibration frequency of the piston impactor ; S3, for specifications and dimensions For the samples, the impact time was estimated for high, medium, and low grade samples to be impacted by a rocker arm impact tester when the sample non-breakage rate was in the range of 45% to 50%. , and In addition, the impact time for high, medium, and low grade samples to be impacted by a piston impactor when the sample breakage rate is in the range of 45% to 50% was estimated. , and ; S4. Apply the estimated impact time of the corresponding high-grade sample to each rocker arm and piston impactor. and Set the impact time; place a high-grade sample into the impact tube of each impactor, then install the impact tube onto the impactor and start each impactor to perform the impact operation. S5. The impacted samples are sieved and weighed to obtain the impact time for the rocker arm impactor. T rH1 Impact failure rate P rH1 Impact time of piston impactor T pH1 Impact failure rate P pH1 , P rH1 and P pH1 The unbroken rate is between 45% and 50%. S6. When the unbroken rate of a sample impacted by a rocker arm impactor or piston impactor is less than 45%, appropriately reduce the impact time of the corresponding sample, and perform the same impact with a new, identical sample until the unbroken rate of the sample is between 45% and 50%. At this point, record the impact time of the rocker arm impactor. and the non-fracture rate of its impact specimens Impact time of piston impactor and the non-fracture rate of its impact specimens ; S7. Following S4 to S6, estimate the impact time using two types of impact testers for medium-grade and low-grade samples, respectively. and as well as and The samples were impacted using a suitable impactor, then sieved and weighed to obtain the impact time of the rocker arm impactor on the medium-grade samples. and the unbroken rate of the sample Impact time of piston impactor on medium-grade sample and the unbroken rate of the sample And the impact time of the rocker arm impactor on low-grade samples. and the unbroken rate of the sample Impact time of piston impactor on low-grade samples and the unbroken rate of the sample ; S8. Following steps S1 to S7, conduct impact tests on high-grade, medium-grade, and low-grade samples using a rocker arm impact tester and a piston impact tester, respectively. The non-breakage rate of the samples after impact should be between 50% and 55%. When the non-breakage rate of a sample impacted by the rocker arm impact tester or piston impact tester is greater than 55%, appropriately increase the impact time of the corresponding sample and perform the same impact test with a new, identical sample until the non-breakage rate of the sample is between 50% and 55%. At this point, record the impact time of the rocker arm impact tester on the samples of the three grades. , and and the corresponding non-fracture rate of the impact specimen , and Impact time of piston impactor on three grades of samples , and and the non-fracture rate of its impact specimens , and ; S9. Using formulas (1), (2), and (3), calculate the impact time for high-grade, medium-grade, and low-grade samples when the breakage rate is 50%, respectively, using a rocker arm impactor. , and This is then further converted into the corresponding number of impact cycles. , and : （1） （2） （3） S10. Using formulas (4), (5), and (6), calculate the impact time for high-grade, medium-grade, and low-grade samples when the non-breakage rate is 50%, respectively, using a piston impactor. , and This is then further converted into the corresponding number of impact cycles. , and : （4） （5） （6） S11. Using formulas (7), (8), and (9), calculate the number of impact cycles of the piston impact tester for the three grades of samples. , and Number of impact cycles for the corresponding grade of sample using a rocker impact tester , and than , and : （7） （8） （9） S12. Using formula (10), calculate the impact cycle ratio of the three grades of samples. , and average r A50 : r A50 （10） S13. Following steps S1 to S12, repeat the parallel tests using the same sample grade and batch number as in steps S1 to S12. Take the average of the two parallel tests as the result. R A50 ; S14, Calculation reduce , or The absolute value of one divided by We obtain three relative percentages. When any one of the three relative percentages is not greater than 1.5%, [ / = / ]≦1.5%, x =H, M, or L; = Execute step S15; when any of the three relative percentages is greater than 1.5%, execute step S16; when the three relative percentages are much greater than 1.5%, that is, when the preset threshold is reached or exceeded, and the expected accuracy is greater than the preset value of the equivalent test result, execute step S17. S15. At this point, the equivalent test results of each grade of sample were obtained by impacting with a piston impactor or a rocker arm impactor. or The calculation does not consider the relative percentage grade relationship when in a sample size specification. The impact test results of any new sample of any grade subjected to impact testing using a rocker arm impact tester or a piston impact tester are as follows: or Equivalent test results of impacting the same sample with a piston impactor or rocker arm impactor different from the previous impactor. or Calculate using either formula (11) or formula (12) respectively: （11） （12） S16. At this point, any one of the three relative percentages is greater than 1.5%, [ / = / >1.5%, equivalent test results of samples of each grade using a piston impact tester or rocker arm impact tester. or The calculations take into account the relative percentage grade relationship. In this case, the equivalent test results of a piston impactor or rocker arm impactor for high-grade samples are... or The equivalent test results of the medium-grade sample are or The equivalent test results for low-grade samples are or When in a sample size specification New samples of medium-high grade, medium grade, and low grade were subjected to impact tests using a rocker arm impact tester or a piston impact tester. The corresponding test results for high-grade samples were... or The medium grade is or And the lower grade is or Equivalent test results of three grades of the same sample tested using a piston impactor or rocker arm impactor, different from the previous impactor. or , or , or Calculate using formulas (13), (14), (15), (16), (17), or (18) respectively: （13） （14） （15） （16） （17） （18） S17. At this point, the three relative percentages are much greater than 1.5%, and the expected accuracy is greater than the preset value. For the equivalent test results, the number of grade layers of the test sample of the same size is increased to 5 or 7 grades. In this case, referring to steps S1 to S16, the equivalent calculation formula for 5 or 7 grades of samples in one size is reconstructed, and then these formulas are applied to calculate the equivalent test results between the rocker arm impactor and the piston impactor.

2. The method as described in claim 1, characterized in that, Step S17 is followed by: Step S18, converting the equivalent number of impact cycles for the three grades of piston impactor and rocker arm impactor into equivalent impact time according to formulas (19) and (20): （19） （20） This allows us to obtain equivalent test results for samples of different grades of superhard abrasives of the same size when tested using a piston impact tester and a rocker arm impact tester.

3. The method as described in claim 2, characterized in that, After step S18, step S19 is also included, obtaining equivalent test results of samples of each grade in all sizes of superhard abrasives tested between a piston impact tester and a rocker arm impact tester.

4. The method as described in claim 1, characterized in that, In step S2, set =2 400r / min.

5. The method as described in claim 1, characterized in that, In step S2, set =1,420 r / min.

6. The method as described in claim 1, characterized in that, When the three relative percentages are much greater than 1.5%, that is, reach or exceed 3.0%, and the equivalent test result with expected accuracy greater than the preset value is obtained, proceed to step S17.

7. The application of the method as described in any one of claims 1 to 6 in the field of superhard abrasive impact toughness testing technology.

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