A method for determining oxygen content in nickel-based high-temperature alloy powder

Abstract

The present invention provides a method for determining the oxygen content in nickel-based high-temperature alloy powder, comprising: using a lump nickel foil as a flux, performing blank correction on the flux, and obtaining a blank correction value; performing correction on a standard substance, and obtaining a standard substance correction value; testing a control sample 1, obtaining a control sample 1 test value, and judging whether the control sample 1 test value is within the certification value range, if it is within the certification value range, the correction is effective; taking a step power test method to test a sample, and obtaining a sample test value; testing a control sample 2, obtaining a control sample 2 test value, and judging whether the control sample 2 test value is within the certification range, if it is within the certification range, the sample test value is reliable. The method reduces the deviation of the fine powder detection result and improves the precision of the fine powder detection result.

Description

Technical Field

[0001] The invention relates to the technical field of powder metallurgy, and in particular to a method for determining the oxygen content in nickel-based high-temperature alloy powder. Background Art

[0002] Nickel-based superalloys are widely used in the aerospace field and have become the preferred material for key parts of aero-engines. Oxygen in nickel-based superalloy powders, especially oxygen adsorbed on the surface of particles, will cause the powder to precipitate continuously distributed network carbides at the boundaries of powder particles during hot isostatic pressing, which will seriously hinder the diffusion connection between particles to form a weak interface, and become the source area and expansion channel for the preferential formation of cracks. In addition, the oxygen content of the powder will also affect the formation of thermally induced pores. This reduces the comprehensive performance of the alloy. Therefore, in the entire process from powder preparation to final forming into a product, the oxygen content of the powder needs to be strictly controlled to ensure the comprehensive performance of nickel-based superalloy powder metallurgy products.

[0003] The detection method currently used is a unified detection method, that is, a unified detection method is adopted regardless of the powder particle size. However, the precision of the oxygen content test results of powders of different particle sizes obtained in this way is not the same. In comparison, the precision of the results obtained from fine powders is slightly worse, and the existing analysis power is relatively low. Some powders may not be fully melted, resulting in the inability to fully release the oxygen content in the powder. Therefore, the reliability of the oxygen content test results of fine powders obtained by the unified test method is not high. Summary of the invention

[0004] The main purpose of the present invention is to provide a method for determining the oxygen content in nickel-based high-temperature alloy powder so as to solve the problems of the prior art.

[0005] In order to achieve the above object, the present invention provides a method for determining the oxygen content in nickel-based high-temperature alloy powder, comprising:

[0006] Using a lump of nickel foil as a flux, performing blank correction on the flux to obtain a blank correction value;

[0007] Calibrate the standard substance to obtain the calibration value of the standard substance;

[0008] Testing the control sample 1 to obtain the test value of the control sample 1, and determining whether the test value of the control sample 1 is within the certified value range. If it is within the certified value range, the calibration is effective.

[0009] Adopt the step power test method to test the sample and obtain the sample test value;

[0010] Test control sample 2 to obtain a test value of control sample 2, and determine whether the test value of control sample 2 is within the certification range. If it is within the certification range, the test value of the sample is reliable.

[0011] Optionally, the test method of using step power to test the sample specifically includes: setting the analysis power to gradient power, selecting constant temperature in the first stage power mode 1, analysis power: 4000W~5500W, time: 10S~30S; selecting constant temperature in the second stage power mode 2, analysis power: 6000W~7000W, time: 70S~80S.

[0012] Optionally, before blank calibration of the flux, the method further comprises: cutting the nickel foil into (0.15-1) g strips, ultrasonically cleaning with alcohol three times, each time for (3-6) min, and rolling into balls and capsules after drying for later use.

[0013] Optionally, the blank correction of the flux specifically includes: putting the rolled nickel foil into the equipment for multiple tests, obtaining a blank test average value and determining whether it is within a preset threshold range, and using the blank test average value as a blank correction value.

[0014] Optionally, the calibration of the standard substance to obtain the calibration value of the standard substance specifically includes: accurately weighing the mass of the standard substance and inputting it into the device as a parameter, putting the standard substance and the lump nickel foil into the device for multiple tests, and determining that the deviation is within a preset threshold of the standard substance, and calibrating it.

[0015] Optionally, the testing of control sample 1 to obtain the test value of control sample 1 specifically includes: using another standard substance with a preset threshold value within the certified value of the standard substance as control sample 1, weighing the mass of the control sample and inputting it into the equipment, putting it and the lump nickel foil into the equipment for testing, and determining that the test result is within the certified value range.

[0016] Optionally, the sample test specifically includes: weighing (0.1-0.5) g of the sample and transferring it into a prepared capsule-shaped nickel foil, expelling the air from the capsule-shaped nickel foil and sealing and squeezing it into small pieces, and then putting it into the equipment for multiple tests.

[0017] Optionally, the testing of the control sample 2 to obtain the test value of the control sample 2 specifically includes: taking the standard substance as the control sample 2, weighing the control sample mass and inputting it into the equipment, putting it and the lump nickel foil into the equipment for testing and determining that the test result is within its certified value range.

[0018] Optionally, all steps include the operation of changing the crucible, the inner crucible is replaced for each test, and the outer crucible is replaced after 6 to 9 tests.

[0019] Optionally, the powder is A3 high temperature alloy powder with a particle size of (0-53) μm, GSB 03-2847-2012 is used as the standard material, GSB 03-2846-2012 is used as control sample 1, and the standard material GSB 03-2847-2012 is used as control sample 2.

[0020] The beneficial effects of the present invention are: reducing the deviation of the detection result of powder, especially fine powder, and improving the precision of the detection result of fine powder.

[0021] Other features and advantages of the present invention will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the following specific embodiments, they are used to explain the present invention but do not constitute a limitation of the present invention. In the accompanying drawings:

[0023] Figure 1 A schematic flow chart of a method for determining oxygen content in nickel-based high-temperature alloy powder according to an embodiment of the present invention;

[0024] Figure 2 This is an example diagram of a ball-shaped and capsule-shaped nickel foil according to an embodiment of the present invention;

[0025] Figure 3 This is an example diagram of a graphite crucible according to an embodiment of the present invention. DETAILED DESCRIPTION

[0026] The specific implementation of the present invention is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described here is only used to illustrate and explain the present invention, and is not used to limit the present invention.

[0027] like Figure 1 As shown, a method for determining the oxygen content in nickel-based high-temperature alloy powder according to an embodiment of the present invention is shown, comprising:

[0028] Step 1: using a lump nickel foil as a flux, performing a blank correction on the flux to obtain a blank correction value;

[0029] Step 2: Calibrate the standard substance to obtain the calibration value of the standard substance;

[0030] Step 3: Test the control sample 1 to obtain the test value of the control sample 1, and determine whether the test value of the control sample 1 is within the certified value range. If it is within the certified value range, the calibration is valid.

[0031] Step 4: Use the step power test method to test the sample and obtain the sample test value;

[0032] Step 5: Test the control sample 2 to obtain the test value of the control sample 2, and determine whether the test value of the control sample 2 is within the certification range. If it is within the certification range, the test value of the sample is reliable.

[0033] Optionally, the test method of using step power to test the sample specifically includes: setting the analysis power to gradient power, selecting constant temperature in the first stage power mode 1, analysis power: 4000W~5500W, time: 10S~30S; selecting constant temperature in the second stage power mode 2, analysis power: 6000W~7000W, time: 70S~80S.

[0034] The main function of the first-stage power mode 1 is to form a molten pool of high-purity nickel foil as a flux, to initially melt the powder and release some oxygen; the main function of the second-stage power mode 2 is to fully melt the powder and fully release the oxygen in the powder by setting a high analytical power. The setting of gradient power can solve the problem of low precision and low reliability of the oxygen content test results of fine powder in the current method.

[0035] Optionally, before blank calibration of the flux, the method further comprises: cutting the nickel foil into (0.15-1) g strips, ultrasonically cleaning with alcohol three times, each time for (3-6) min, and rolling into balls and capsules after drying for later use.

[0036] Optionally, the blank correction of the flux specifically includes: putting the rolled nickel foil into the equipment for multiple tests, obtaining a blank test average value and determining whether it is within a preset threshold range, and using the blank test average value as a blank correction value.

[0037] Optionally, the calibration of the standard substance to obtain the calibration value of the standard substance specifically includes: accurately weighing the mass of the standard substance and inputting it into the device as a parameter, putting the standard substance and the lump nickel foil into the device for multiple tests, and determining that the deviation is within a preset threshold of the standard substance, and calibrating it.

[0038] Optionally, the testing of control sample 1 to obtain the test value of control sample 1 specifically includes: using another standard substance with a preset threshold value within the certified value of the standard substance as control sample 1, weighing the mass of the control sample and inputting it into the equipment, putting it and the lump nickel foil into the equipment for testing, and determining that the test result is within the certified value range.

[0039] Optionally, the sample test specifically includes: weighing (0.1-0.5) g of the sample and transferring it into a prepared capsule-shaped nickel foil, expelling the air from the capsule-shaped nickel foil and sealing and squeezing it into small pieces, and then putting it into the equipment for multiple tests.

[0040] Optionally, the testing of the control sample 2 to obtain the test value of the control sample 2 specifically includes: taking the standard substance as the control sample 2, weighing the control sample mass and inputting it into the equipment, putting it and the lump nickel foil into the equipment for testing and determining that the test result is within its certified value range.

[0041] Optionally, all steps include the operation of changing the crucible, the inner crucible is replaced for each test, and the outer crucible is replaced after 6 to 9 tests.

[0042] Optionally, the powder is A3 high temperature alloy powder with a particle size of (0-53) μm, GSB 03-2847-2012 is used as the standard material, GSB 03-2846-2012 is used as control sample 1, and the standard material GSB 03-2847-2012 is used as control sample 2.

[0043] A method for determining the oxygen content in a nickel-based high-temperature alloy powder provided by an embodiment of the present invention is described in detail below, comprising the following steps:

[0044] Preparation before the test:

[0045] Cut the nickel foil into (0.15-1)g strips, clean them three times with alcohol ultrasonic, each time for (3-6)min, dry them and roll them into balls and capsules for later use. Figure 2 As shown, example diagrams of ball-shaped and capsule-shaped nickel foils according to embodiments of the present invention are shown.

[0046] Test steps:

[0047] Using nickel foil as flux, performing blank correction on the flux to obtain a blank correction value;

[0048] The rolled nickel foil is put into the equipment for multiple tests, and the blank test average value is obtained and determined to be within the preset threshold range (i.e., less than 0.0005%), and the blank test average value is used as the blank correction value. The number of parallel blank determinations should be greater than or equal to 3 times.

[0049] Calibrate the standard substance to obtain the calibration value of the standard substance;

[0050] Accurately weigh the mass of the standard substance and input it into the device as a parameter. Put the standard substance and the lumped nickel foil into the device for multiple tests, and make sure that the deviation is within the preset threshold of the standard substance, and calibrate it. The number of parallel determinations of the standard sample should be greater than or equal to 3 times.

[0051] Testing the control sample 1 to obtain the control sample test value, and determining whether the control sample test value is within the certified value range. If it is within the certified value range, the calibration is effective.

[0052] A standard substance with another preset threshold within the certified value of the standard substance in step 2) is used as control sample 1, the control sample mass is weighed and input into the equipment, it and the ball-shaped nickel foil are put into the equipment for testing, and it is determined that the test result is within its certified value range.

[0053] Conduct sample testing and obtain sample test values;

[0054] Weigh (0.1-0.5)g of the sample and transfer it into the prepared capsule-shaped nickel foil, expel the air from the capsule-shaped nickel foil, seal it and squeeze it into small pieces, and put it into the equipment for multiple tests. The number of parallel test samples should be greater than or equal to 3 times.

[0055] This step is the key step of this method. The main point is that the power setting in the equipment parameter "analytical furnace" setting should be set to step power, that is, it has two power modes.

[0056] Test the control sample 2 to obtain the control sample test value, and determine whether the control sample test value is within the certified value range. If it is within the certified value range, the sample test value is reliable.

[0057] The standard substance described in step 2) is used as control sample 2, the control sample mass is weighed and input into the equipment, and it and the ball-shaped nickel foil are put into the equipment for testing and it is determined that the test result is within its certified value range.

[0058] All steps include the operation of changing the crucible. The inner crucible is replaced for each test, and the outer crucible is replaced after 6 to 9 tests. The specific operation depends on the actual situation in the actual test, such as Figure 3 As shown, an example diagram of a graphite crucible according to an embodiment of the present invention is shown.

[0059] The following is a method for determining the oxygen content in a nickel-based high-temperature alloy powder according to an embodiment of the present invention, which is further described by way of example:

[0060] The instruments used in the measurement process include but are not limited to: oxygen, nitrogen and hydrogen analyzer, analytical balance, and ultrasonic cleaning machine.

[0061] The equipment measurement conditions are set as follows: automatic sample placement; analysis delay: 20S~30S; vacuum opening time: 10S~20S; integration time: 80S~100S.

[0062] Furnace degassing settings: select constant temperature in power mode; degassing power: 5500W~6000W; degassing time: 20S~30S.

[0063] Analytical furnace gradient power setting: in the first stage, power mode 1 selects constant temperature, analysis power: 4000W~5500W, time: 10S~30S; in the second stage, power mode 2 selects constant temperature, analysis power: 6000W~7000W, time: 70S~80S.

[0064] Reagents and consumables used in the determination process:

[0065] Alcohol: analytical grade.

[0066] Flux type: high purity nickel foil.

[0067] Preparation of flux: Nickel foil is cut into (0.15-1)g strips before use, cleaned three times with alcohol ultrasonically, 3 minutes each time, and rolled into balls and capsules after drying for later use.

[0068] Graphite crucible: set crucible, see attached Figure 3 .

[0069] Standard materials: GSB 03-2847-2012, GSB 03-2846-2012.

[0070] The sample weighing method is as follows: the sample to be tested is a nickel-based high-temperature alloy powder sample. Use weighing paper to roughly weigh (0.1-0.5) g of the sample, then move the sample into the prepared capsule-shaped nickel foil, use tweezers to remove the air in the capsule-shaped nickel foil as much as possible, seal it and squeeze it into small pieces, weigh the mass of the wrapped powder sample and input it into the equipment, and the sample is ready for testing.

[0071] The example is explained by taking the determination of the oxygen content in the powder of A3 high temperature alloy (0-53) μm particle size as an example.

[0072] The specific testing process is as follows:

[0073] 1. Perform a blank calibration on the flux.

[0074] The equipment selected blank analysis, put the aforementioned lump nickel foil into the equipment for testing, repeated the test 3 times for the flux blank value, and the obtained test average value was less than 0.0005%, that is, within the threshold range, and the next test was carried out after correction and storage.

[0075] The flux blank test value data are as follows:

[0076] name Oxygen average value / % Oxygen standard deviation / % Nickel Foil Blank 0.00007 ±0.00003 Serial number Oxygen concentration / % 1 0.00011 2 0.00004 3 0.00007

[0077] As described above, the blank test average value obtained from the blank test is 0.00007, and this test value is used as the blank correction value for correction.

[0078] 2. Calibrate the standard substance and obtain the calibration value of the standard substance.

[0079] In this example, GSB 03-2847-2012 is selected as the standard material, and its certified oxygen content value is 0.0166% ± 0.0004%.

[0080] The equipment selects the standard substance for detection, accurately weighs the mass of the standard substance and inputs it into the equipment, puts the prepared nickel foil into the injection port, and then puts the standard substance in for the standard substance test. Repeat the test 3 times, and the deviation of the test value is less than 0.0002%, and the calibration is saved.

[0081] The test results of the standard substances are as follows:

[0082]

[0083]

[0084] As mentioned above, the average value of the standard substance test is 0.0166%, which is used as the standard substance correction value.

[0085] 3. Conduct control sample 1 test

[0086] After completing blank calibration and standard substance calibration, select the standard substance GSB 03-2846-2012 with a known content as control sample 1, and its certified oxygen content value is 0.0058% ± 0.0002%. Monitor the accuracy of the test after calibration.

[0087] The equipment selects the sample for testing. Accurately weigh the mass of the standard substance and input it into the equipment, put the ball of nickel foil into the sample inlet, then put the standard substance in, and test the control sample. After the test is completed, compare the test value with the certified value to see if it is within the tolerance range.

[0088] The test results of control sample 1 are as follows:

[0089] name Oxygen concentration / % Control sample 1 0.0059

[0090] From the above test results, it can be seen that the test value of control sample 1 is within the certified range, and the test results after calibration are reliable.

[0091] 4. Conduct sample testing

[0092] The equipment selects the sample for testing. Weigh (0.1-0.5)g of the sample with weighing paper and transfer it into the prepared capsule-shaped nickel foil. Use tweezers to remove the air in the capsule-shaped nickel foil as much as possible and seal it to squeeze it into small pieces. The analytical balance accurately weighs the mass of the sample powder and inputs it into the equipment for sample testing. Parallel measurements are performed 3 times to obtain the final test results.

[0093] The sample test results are as follows:

[0094]

[0095]

[0096] The average oxygen content of the above powder samples is: 0.0244%, the standard deviation is: ±0.0013%, and the relative standard deviation is: 5.20%.

[0097] name Oxygen average value / % Oxygen standard deviation / % Sample-2 0.0138 ±0.0004 Serial number Oxygen concentration / % 1 0.0132 2 0.0134 3 0.0143

[0098] The average oxygen content of the above powder samples is: 0.0138%, the standard deviation is: ±0.0004%, and the relative standard deviation is: 2.80%.

[0099] 5. Test control sample 2

[0100] After completing the sample test, the standard substance GSB 03-2847-2012 with a known content was selected as control sample 2 to monitor the reliability of the test results. The certified value of its oxygen content was 0.0166% ± 0.0004%.

[0101] The equipment selects the sample for testing. Accurately weigh the mass of the standard substance and input it into the equipment, put the ball of nickel foil into the sample inlet, then put the standard substance in, and test the control sample. After the test is completed, compare the test value with the certified value to see if it is within the tolerance range.

[0102] The test results of control sample 2 are as follows:

[0103] name Oxygen concentration / % Control sample 2 0.0169

[0104] From the above test results, it can be seen that the test value of control sample 2 is within the certified range, and the test results after calibration are reliable.

[0105] It can be seen from this that the sample oxygen content measured in step 4 is accurate and reliable.

[0106] The preferred embodiments of the present invention are described in detail above in conjunction with the accompanying drawings. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, a variety of simple modifications can be made to the technical solution of the present invention, and these simple modifications all belong to the protection scope of the present invention.

[0107] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0108] In addition, various embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed by the present invention.

Claims

1. A method for determining the oxygen content in nickel-based high-temperature alloy powder, characterized in that: include: Using a lump of nickel foil as a flux, performing blank correction on the flux to obtain a blank correction value; Calibrate the standard substance to obtain the calibration value of the standard substance; Using another standard substance whose preset threshold is within the certified value of the standard substance as control sample 1, testing control sample 1 to obtain a test value of control sample 1, and judging whether the test value of control sample 1 is within the certified value range. If so, the calibration is effective. A step power test method is adopted to test the sample and obtain the sample test value; the step power test method for testing the sample specifically includes: setting the analysis power to gradient power, selecting constant temperature in the first stage power mode 1, analysis power: 4000W~5500W, time: 10S~30S; selecting constant temperature in the second stage power mode 2, analysis power: 6000W~7000W, time: 70S~80S; wherein, the main function of the first stage power mode 1 is to form a molten pool of high-purity nickel foil as a flux, to initially melt the powder and release part of the oxygen; the main function of the second stage power mode 2 is to fully melt the powder by setting a high analysis power, and to fully release the oxygen in the powder; The standard substance is used as control sample 2, and control sample 2 is tested to obtain a test value of control sample 2, and it is determined whether the test value of control sample 2 is within the certification range. If it is within the certification range, the test value of the sample is reliable; Among them, the testing of control sample 1 and obtaining the test value of control sample 1 specifically includes: using another standard substance with a preset threshold value within the certified value of the standard substance as control sample 1, weighing the mass of the control sample and inputting it into the equipment, putting it and the lump nickel foil into the equipment for testing, and determining that the test result is within its certified value range.

2. The method according to claim 1, characterized in that Before blank correction is performed on the flux, the method further comprises: cutting the nickel foil into strips of 0.15-1 g, washing it three times with alcohol ultrasonically, each time for 3-6 minutes, and rolling it into balls and capsules after drying for later use.

3. The method according to claim 2, characterized in that The blank correction of the flux specifically includes: putting the rolled nickel foil into the equipment for multiple tests, obtaining the blank test average value and determining whether it is within a preset threshold range, and using the blank test average value as the blank correction value.

4. The method according to claim 3, characterized in that The calibration of the standard substance and obtaining the calibration value of the standard substance specifically include: accurately weighing the mass of the standard substance and inputting it into the device as a parameter, putting the standard substance and the lump nickel foil into the device for multiple tests, and determining that the deviation is within the preset threshold of the standard substance, and calibrating it.

5. The method according to claim 4, characterized in that The sample test specifically includes: Weigh 0.1~0.5g of the sample and transfer it into the prepared capsule-shaped nickel foil. Expel the air from the capsule-shaped nickel foil, seal it and squeeze it into small pieces, which are then put into the equipment for multiple tests.

6. The method according to claim 5, characterized in that The testing of the control sample 2 to obtain the test value of the control sample 2 specifically includes: using the standard substance as the control sample 2, weighing the control sample mass and inputting it into the equipment, putting it and the lump nickel foil into the equipment for testing and determining that the test result is within its certified value range.

7. The method according to claim 6, characterized in that All steps include the operation of changing the crucible. The inner crucible is replaced for each test, and the outer crucible is replaced after 6 to 9 tests.

8. The method according to claim 7, characterized in that The powder is A3 high temperature alloy powder with a particle size of 0-53 µm, GSB 03-2847-2012 is used as the standard material, GSB 03-2846-2012 is used as the control sample 1, and the standard material GSB 03-2847-2012 is used as the control sample 2.

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