GOST 9450-76
GOST 9450−76 (ST SEV 1195−78) Measurement of the microhardness indentation of the diamond tips (with Amendments No. 1, 2)
GOST 9450−76
(ST CMEA 1195−78)
Group Т59
STATE STANDARD OF THE USSR
MICROHARDNESS TESTING
THE INDENTATION OF THE DIAMOND TIPS
Measurements microhardness by diamond instruments indentation
Date of introduction 1977−01−01
INFORMATION DATA
1. DEVELOPED AND INTRODUCED by the Academy of Sciences of the USSR
DEVELOPERS:
Matveevsky R. M., doctor of engineering. Sciences (head of subject); Berkovich, E. S., Cand. tech. Sciences; Rynkov R. H., PhD. tech. Sciences
2. APPROVED AND promulgated by the Decree of the State Committee of standards of Ministerial Council of the USSR from
3. The check date — 1996;
the frequency of inspection — 5 years
4. REFERENCE NORMATIVE AND TECHNICAL DOCUMENTS
| The designation of the reference document referenced |
The number of the paragraph, subparagraph, enumeration, applications |
| GOST 2789−73 |
4.1 |
| GOST 9377−81 |
Annex 2 |
| TU 3−3.1377−83 |
3.1; 3.2; 3.4; 3.5 |
5. Proven in 1991 by the Resolution of Gosstandart N 1665
6. REPRINT (March 1993) with Amendments No. 1, 2 approved in September 1981, October 1991 (IUS 11−81, 1−92)
This standard specifies a method for the measurement of the microhardness of the products and samples of metals, alloys, minerals, glass, plastics, semiconductors, ceramics, thin sheets, foils, films, electroplating, diffusion, chemically precipitated and electrodeposited coatings by the indentation of the diamond tips.
Test materials the hardness is limited to the products (samples) of diamond and their derivatives.
The standard specifies two test methods:
in the restored print (priority);
on the unreduced fingerprint (optional method).
This standard complies ST SEV 1195−78 in measuring the microhardness of metals by the method of the restored print four-sided pyramid with a square base (Vickers).
1. TEST METHOD OF THE RESTORED PRINT
1.1. The test of microhardness indentation method of the restored print is applied to the test surface of the product (sample) of the print by static load applied to the diamond tip during a certain time. After removal of the load and measurement of parameters of the received fingerprint, the number of microhardness should be determined according to the formulas (see PP.1.4−1.7) or at the table.1−28, is given in Appendix 1.
1.2. When testing you should use diamond tips, the shape of the working part which should correspond specified in the table. Guidance on the choice of tips is given in Annex 2.
1.3. The number of microhardness is determined by dividing the applied to the diamond tip normal load on conventional lateral surface area of the resulting print.
1.4. For four-sided pyramid with a square base, the number of the microhardness is calculated by the formula
if expressed in Newtons
if expressed in kilogram-forces).
1.5. For a triangular pyramid with base an equilateral triangle the number of the microhardness 
if expressed in Newtons
if expressed in kilogram-forces).
1.6. For four-sided pyramid with a rhombic base, the number of the microhardness is calculated by the formula
if expressed in Newtons
if expressed in kilogram-forces).
1.7. For bicylindrical tip number microhardness () should be calculated according to the formula
if expressed in Newtons
(
if expressed in kilogram-forces).
In formulas (1) to (4) the following notation: — normal load applied to the diamond tip, N (kgf);
the conditional lateral surface area of the obtained print, mm
;
— print size, mm;
— the arithmetic mean of the lengths of both diagonals of the square imprint, mm;
— the radius of the cylinder is 2 mm;
and
the different angles of sharp diamond tips, Gras
D.
1.8. Microhardness, defined by PP.1.4−1.7, denote ,
,
and
, indicating the load in kgf and duration of its application. For the microhardness of the
duration of load application do not indicate if it is in the range of 10−15 C.
Examples of symbols
Microhardness defined four-sided pyramid with a square base with a load of 0,098 N applied for 15 s: 0,01.
Microhardness defined four-sided pyramid with a square base with a load of 0.98 N applied for 30 s: 01/30.
Microhardness, a certain triangular pyramid with base an equilateral triangle with a load of 0,0491 N applied for 5 s: 0,005/5.
Microhardness defined four-sided pyramid with a rhombic base with a load of 0,098 N applied for 10 s: 0,01/10.
2. TEST METHOD UNRESTORED PRINT
2.1. Determination of microhardness by indentation method unrestored print is applied to the test surface of the product (sample) of the print by static load applied to the diamond tip during a certain time, with simultaneous measurement of the depth of the imprint. The number of microhardness should be determined according to the formulas (5) to (8).
2.2. Test method unrestored print should be carried out when additional material characteristics (elastic recovery, relaxation, creep at normal temperature).
2.3. When testing used diamond tips with the shape of the work piece shown in the table.
2.4. The number of microhardness is determined by dividing the applied to the diamond tip normal load on conventional lateral surface area of the imprint corresponding to its measured depth.
2.5. For four-sided pyramid with a square base, the number of the microhardness 
if expressed in Newtons
if expressed in kilogram-forces).
2.6. For a triangular pyramid with base an equilateral triangle the number of the microhardness 
if expressed in Newtons
if expressed in kilogram-forces).
2.7. For four-sided pyramid with a rhombic base, the number of the microhardness 
if expressed in Newtons;
if expressed in kilogram-forces).
2.8. For bicylindrical tip of microhardness number () is calculated by the formula
if expressed in Newtons;
(
if expressed in kilogram-forces).
In formulas (5)-(8) the following notation: — normal load applied to the diamond tip, N (kgf);
the conditional lateral surface area of the obtained print, mm
;
the depth of the imprint, mm.
2.9. Formula (5), (6), (7) and (8) are obtained from the ratios between sizes or
tall and
rigid geometric bodies forms a working part of diamond tips (see table):
| The name diamond lugs |
The parameters for sharpening diamond bits |
Form prints |
| 1. Four-sided pyramid with a square base |
|
|
| 2. Triangular pyramid with base an equilateral triangle |
|
|
| 3. Four-sided pyramid with a rhombic base |
|
|
| 4. Ballisticheskih tip |
|
°
; 
; 
; 
;
mm — the radius of the cylinder
2.10. Microhardness determined from PP.2.5−2.8, denoted, respectively ,
,
and
with indication of load in kgf and duration of its application.
Examples of symbols
Microhardness determined from the height of unrestored print four-sided pyramid with a square base with a load of 0,098 N applied for 15 c: 0,01/15.
Microhardness determined from the height of unrestored print bicylindrical tip under load 0,0491 N applied for 5 s: 0,005/5.
3. EQUIPMENT
3.1. To measure the microhardness diamond tips used devices on the other 3−3.1377−83.
3.2. The devices complement the diamond tips in accordance with the requirements set out in THAT 3−3.1377−83.
3.3. In the process of testing the device for measuring the microhardness must ensure compliance with the following conditions:
smooth implementation of the diamond tip into the test material under the applied to it a normal load ;
the persistence of the action attached to the diamond tip the load within the stipulated time;
permissible error of the load must not exceed:
for loads of 0.1 N and less than 2% of the nominal value;
for loads of more than 0.1 H — 1% from the nominal value.
3.4. The device must be protected from the effects of possible vibrations transmitted through walls, floors of buildings or across the table on which the appliance is installed damping device referred to in THAT 3−3.1377−83.
3.5. Checking instruments before the test is the same in 3−3.1377−83.
3.6. The device must be equipped with the microscope for counting the prints. The calibration factor of the microscope should be installed so that the error does not exceed ±0,5% of the measured value.
Minimum magnification should be:
200 — for prints over 25 microns;
300for prints from 76 to 125 microns;
400for prints less than 76 microns.
Note. To measure the print with increasing 200use a lens with an aperture of at least 0.4.
4. PREPARING FOR THE TEST
4.1. The surface of the test products (sample) must be free from contamination at the site of application of the imprint. Roughness test the surface of the product (sample) should not be coarser 
4.2. In preparing the surface of the test products (sample), you must take precautions due to possible change in the hardness of the tested surface due to heating or work hardening when machining.
4.3. Tested product (sample) must be set on the object table of the device so that in the process of testing it does not move, does not bend and is not rotated.
4.4. The surface of the product (sample) to be tested must be installed perpendicular to the axis of the diamond tip.
4.5. The working surface of the diamond tip and the surface of the test items should be dry (without lubrication).
5. TESTING
5.1. When the test material (sample) on microhardness indentation applied load 0,049 (0,005); 0,0981 (0,01); 0,1962 (0,02); 0,4905 (0,05); 0,981 (0,1); 1,962 (0,2) or 0,0491 (0,005); 0,0981 (0,01); 0,1962 (0,02); 0,4905 (0,05); 0,981 (0,1); 1,962 (0,2); 4,905 (0,5) N (kgf).
In determining the microhardness of metals four-sided pyramid with a square base is allowed to apply load 0,0098 (0,001); 0,0196 (0,002) and 2,943 (0,3) N (kgf).
5.2. (Deleted, Rev. N 2).
5.3. To obtain the most accurate measurement of the microhardness of the load must be possible.
5.4. On the side of the product (sample), opposite the subject after application of the imprint must be no traces of deformation of the material, visible to the naked eye.
5.5. When measuring the microhardness of coatings of homogenous material (electroplating, diffusion, case hardening, etc.) on metal or on other materials, the load should be the smaller, the thinner the coating layer. If the thickness of the test layer is unknown, it is recommended to perform multiple tests at different loads: 0,098; 0,196; 0,490; 0,981 N, etc.
If the base material [core products (sample)] does not affect the measurement result, the values of microhardness will coincide or be close to each other.
If the values of microhardness with increasing load will decrease or increase, then the load should be reduced until, until two consecutive loads won’t give the same or similar to each other results.
5.6. The size difference or
one print should not exceed 3% of the smaller value.
5.7. The distance from the center of the print to the edge of the product (sample) should be at least double the size of the print. The distance between the centers of fingerprints deposited on one surface, must not exceed print size by more than three times.
5.8. Loading should be carried out smoothly, without bumps. The lowering speed of the diamond tip should not affect the dimensions of the print. The duration of exposure should be at least 3 s.
5.9. Sizing of prints is performed on the microscope in a bright field with a counting error of ±0.5 of the smallest division of the scale at the magnification lens 30−40 (numerical aperture 
5.10. Tests carried out at ambient temperature (20±5) °C.
5.11. The number of prints and place their application on the product (the sample) must be set in the normative-technical documentation for specific products.
5.12. When measuring the microhardness of products (specimen) with a curved surface when the curvature radius of one to two orders of magnitude larger than the size of the printout, the number of microhardness have conditional values — for comparison, the microhardness of the surfaces of the same curvature.
5.13. When measuring the microhardness of the products (samples) of heterogeneous, porous, anisotropic materials, when the requirements of PP.4.1 and 5.3−5.7 is not feasible, surface roughness, load, time of loading and holding under load, the permissible distortion of the shape of fingerprints, the ratio between the minimum thickness of the layer (sample) and the depth of the imprint, the introduction of correction factors for the curvature of the surface must be established in normative technical documentation for specific products.
6. PROCESSING OF THE RESULTS
6.1. Microhardness is calculated according to the formulas (1) to (8) or find in tables of Annex 1.
6.2. Sizes or
print it measured the depth
found in the table of Annex 3.
6.3. The number of microhardness taking the arithmetic mean of the individual measurements.
6.4. The number of microhardness are allowed to round off to whole units in two-digit or more values and up to one or two decimal places — when unambiguous. The relative error in rounding number of the microhardness shall not exceed 2% of the measured value of the microhardness.
6.5. The test report should indicate:
the designation of the tested product (sample);
device type indicating the characteristics of the applied optics (objective, ocular);
designation microhardness;
print sizes;
the microhardness value.
