GOST 25095-82

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  ГОСТ 25095-82

GOST 25095−82 (ISO 3312−75) sintered hard Alloys. The method of determining the modulus of elasticity (young's modulus) (Change No. 1)

GOST 25095−82
(ISO 3312−75)
Group B59

STATE STANDARD OF THE USSR

SINTERED HARD ALLOYS

The method of determining the modulus of elasticity (young's modulus)

Sintered hardmetals. Method of determination of elastic modulus (of Young’s modulus)

Date of introduction 1983−01−01

INFORMATION DATA

1. DEVELOPED AND INTRODUCED by the Ministry of nonferrous metallurgy of the USSR

DEVELOPERS

N.Kudrya, V. I. Tumanov, A. A. Zaluzhny

2. APPROVED AND put INTO EFFECT by Decision of the USSR State Committee for standards from 21.01.82 N 194

The change in N 1 taken by the Interstate Council for standardization, Metrology and certification (Protocol No. 6 dated 21.10.94)

The adoption voted:

3. REFERENCE NORMATIVE AND TECHNICAL DOCUMENTS

4. REPRINT (January 1998) with amendment No. 1, approved in March 1995 (I & C 5−95)


This standard specifies a method for determining the dynamic (adiabatic) elastic modulus (young's modulus) of sintered hard alloys.

The method consists in the excitation of longitudinal ultrasonic oscillations and the determination of the self-resonant frequency.

Allowed to carry out the determination of the modulus of elasticity according to ISO 3312−75*, is given in Appendix 3.
________________
* Access to international and foreign documents can be obtained by clicking on the link, here and hereafter. — Note the manufacturer’s database.

(Changed edition, Rev. N 1).

1. SAMPLING METHOD

1.1. Sampling when sampling of a mixture of carbide and binder metal according to GOST 20559.

1.2. For tests used samples with a circular cross section with a diameter of 6 mm or a rectangular cross-section 6x8 mm long, 60−65 mm. tolerances for diameter or side section of the specimen shall not exceed ±0.2 mm.

1.3. The surface layer of the sintered samples should be removed from all sides to a depth of not less than 0.1 mm. the surface Roughness should be not more than 1.5 µm churchyard 2789.

1.4. The deviation from parallelism of the ends of the sample should not exceed 0,02 mm. the Deviation from parallelism of the ends of the sample is determined by a dial indicator with a scale division of 0.01 mm according to GOST 577 or other device to ensure the specified accuracy. On the surface of the specimen before the test should be no visible cracks or structural defects.

2. EQUIPMENT

To determine the young’s modulus is used a device consisting of a fixture for sample mounting, the device (generator) for excitation of longitudinal oscillations with continuously adjustable frequency range from 20 kHz to 100 kHz, and device for determining the resonant frequency with an error not more than ±0,2%.

A block diagram is shown in Appendix 1.

3. TESTING

3.1. Tests carried out at a temperature (293) K (20) °C.

3.2. The density of the sample is determined with an accuracy of at least 0.01 g/cmaccording to GOST 20018.

3.3. The length of the sample is measured with a Vernier caliper according to GOST 427 with error of less than 0.1 mm or other device to ensure the specified accuracy.

3.4. The sample is installed in the fixture between the two piezoelectric elements (sensor and receiver) and gradually increase the generator frequency until then, until it reaches the lowest resonant frequency corresponding to the own fluctuations of the sample. Determine the resonance frequency of the device Ф552А for NTD with an accuracy of 0.025% or other device to ensure the specified accuracy.

3.5. Spend at least two measurements on each sample with the opposite directions of the sample set.

4. PROCESSING OF THE RESULTS

4.1. The young’s modulus, GPA, is calculated by the formula

,

where is the length, mm;

 — the density of the sample, g/cm;

 — natural frequency, Hz.

4.2. The calculation of the young’s modulus is carried out with an accuracy not more than 1.5%.

4.3. The figure of the young’s modulus taking the arithmetic average for the samples tested, rounded to the nearest 5 HPa.

4.4. The test results are entered in the Protocol, the form of which is given in Appendix 2.

ANNEX 1 (recommended). A BLOCK DIAGRAM OF APPARATUS TO DETERMINE YOUNG’S MODULUS

ANNEX 1
Recommended

1 — regulated power supply; 2 — the generator of ultrasonic vibrations; 3 — sensor (piezo); 4 — sample; 5 — receiver (piezoelectric element); 6 — screen; 7 — amplifier; 8 — oscilloscope; 9 — frequency

APPENDIX 2 (recommended). TEST REPORT

ANNEX 2
Recommended

TEST REPORT N

APPENDIX 3 (recommended). ISO 3312−75. MATERIALS AND METAL-CERAMIC HARD ALLOYS. DETERMINATION OF YOUNG’S MODULUS

APPENDIX 3
Recommended

MATERIALS AND METAL-CERAMIC HARD ALLOYS. DETERMINATION OF YOUNG’S MODULUS

1. Purpose and scope

This international standard specifies a method for determining the dynamic (adiabatic) young modulus based on the longitudinal vibration of metal materials and hard alloys.

2. The essence of the method

Excitation of ultrasonic longitudinal vibrations in the sample and determining the resonance frequency of its natural oscillations.

3. Symbols and definitions

4. Equipment

4.1. A clamp for mounting the sample.

4.2. Ultrasonic vibrator with continuous frequency regulation in the range of 20−100 kHz.

4.3. A device for determining the resonant frequency.

5. Sampling and preparation of samples for testing

5.1. Samples for test should have a minimum length of 60 mm and can be round or rectangular cross-section. Samples of circular cross section should have a diameter of (6±0,2) mm. Square cross-section flat specimens shall be (6±0,2x8±0,2) mm.

5.2. The surface layer must be removed to a depth of not less than 0.1 mm. the surface Roughness needs to be 1.5 µm.

5.3. The ends of the samples must be flat and parallel with an accuracy of 0.02 mm.

5.4. Samples must not have cracks or any other structural defects and cleaned immediately before testing.

6. Testing

6.1. Determine the density of the sample to the nearest 0.01 g/cm.

6.2. Measure the length of the sample to the nearest 0.1 mm.

6.3. Fasten the sample in the test device. Gradually increase the frequency of the vibrator to the lowest natural frequency of longitudinal vibrations. Determine the resonance frequency with an accuracy of 50 Hz.

7. Processing of the results

7.1. The young’s modulus is calculated by the formula

.

7.2. The result is rounded to an accuracy of 5·10N/mm

8. Test report

The test report should include the following information:

a) a reference to an international standard;

b) all details necessary for identification of the sample;

C) the results obtained;

g) all procedures not specified in this international standard or optional;

d) any deviation that may affect the results.

APPENDIX 3. (Added, Rev. N 1).



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M.: IPK Publishing house of standards, 1998