This document is developed in accordance with the rules given in GB/T 1.1-2020 Directives for standardization - Part 1: Rules for the structure and drafting of standardizing documents.
This document replaces GB/T 5162-2006 Metallic powders - Determination of tap density. In addition to a number of structural adjustments and editorial changes, the following main technical changes have been made with respect to GB/T 5162-2006:
a) The scope is modified (see Clause 1; Clause 1 of Edition 2006);
b) "After consultation and agreement, manual operation can also be used to reinforce" is deleted (see Clause 2 of Edition 2006);
c) "Of appropriate capacity and accuracy to satisfy the requirements shown in Table 2" is changed to "of appropriate capacity to satisfy the requirements shown in Table 2 and of an accuracy to weigh to the nearest 0.1 g" (see 4.1, 4.1 of Edition 2006 );
d) "Table 2" is deleted (see 4.1 of Edition 2006);
e) "Measurement accuracy of ±0.1cm3 " is deleted (see 4.2 of Edition 2006);
f) The labeling method of the example of tapping apparatus in Figure 1 is changed (see Figure 1, Figure 1 of Edition 2006);
g) The requirements of the tapping apparatus is changed to "Tapping apparatus, which permits the tapping of the graduated cylinder against a firm base. The tapping shall be such that a densification of the powder can take place without any loosening of its surface layers." (see 4.3, 4.3 of Edition 2006);
h) "Only after consultation and agreement, the use of hard rubber plates (size approximately 100mm×100mm×5mm) and manual operation of the vibrating method are allowed" is deleted (see 4.3 of Edition 2006);
i) When using a 100cm3 glass measuring cylinder to test, the apparent density "≥1" " is changed to "1~4" (see Table 2, Table 3 of Edition 2006);
j) "Take 3 samples of each sample for testing" is change to "the test shall be carried out on three test portions, if possible." (see 5.3, 5.3 of Edition 2006);
k) "See Figure 1" is changed to "see Note" (see 6.3, 6.3 of Edition 2006);
l) "After consultation and agreement, consolidation can also be carried out in the following ways" is deleted (see 6.3 of Edition 2006);
m) "Vibrate the measuring cylinder on the hard rubber plate by hand until the volume of the powder no longer decreases. At the end of the vibration process, gently vibrate to prevent the surface layer of the powder from becoming loose. (See Note 2)" is deleted (see 6.3 of Edition 2006);
n) "Note 2" is deleted (see 6.3 of Edition 2006);
o) When using a 25cm3 graduated cylinder, "accurate to 0.1 cm3 is changed to "accurate to 0.2 cm3 " (see 6.4, 6.4 of Edition 2006);
p) "Take the arithmetic average of three measurement results and report the final result" is changed to "report the arithmetical mean of the number of determinations" (see Clause 7, Clause 7 of Edition 2006);
q) "Details of any occurrence which may have affected the result" is added (see Clause 8, Clause 8 of Edition 2006).
The translation method used in this document is equivalent to ISO 3953:2011 Metallic powders - Determination of tap density.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. The issuing body of this document shall not be held responsible for identifying any or all such patent rights.
This document was proposed by China Nonferrous Metals Industry Association.
This document is under the jurisdiction of SAC/TC 243 National Technical Committee on Nonferrous Metals of Standardization Administration of China.
The previous editions of this document and documents replaced by this document are as follows:
——GB/T 5162-1985 was first published in 1985, and the first revision in 2006;
——This edition is the second revision.
Metallic powders - Determination of tap density
1 Scope
This document specifies a method for the determination of tap density, i.e. the density of a powder that has been tapped into a container under specified conditions.
2 Principle
A specified amount of powder in a container is tapped by means of a tapping apparatus until no further decrease in the volume of the powder takes place. The mass of the powder divided by its volume after the test gives its tap density.
3 Symbols
For the purposes of this document, the symbols in Table 1 apply.
Table 1 Symbols
Symbol Meaning Unit
pt Tap density g/cm3
m Mass of the powder g
V Volume of the tapped powder cm3
4 Apparatus
4.1 Balance
Balance, of appropriate capacity to satisfy the requirements shown in Table 2 and of an accuracy to weigh to the nearest 0.1 g.
4.2 Graduated glass cylinder
Graduated glass cylinder, calibrated to contain 100 cm3, the height of the graduated portion being approximately 175 mm. The graduations shall be at 1 cm3 intervals, thus allowing a measuring accuracy of ±0.5 cm3.
Graduated glass cylinder, calibrated to contain 25 cm3, the height of the graduated portion being approximately 135 mm. The graduations shall be at 0.2 cm3 intervals.
A 25 cm3 cylinder shall be used for powders of apparent density higher than 4 g/cm3, in particular for refractory metal powders, but may also be used for powders of lower apparent density.
4.3 Tapping apparatus
Tapping apparatus, which permits the tapping of the graduated cylinder against a firm base. The tapping shall be such that a densification of the powder can take place without any loosening of its surface layers. The stroke shall be 3 mm and the tapping frequency shall be between 100 and 300 taps/min. An example of a tapping apparatus is shown in Figure 1.
Dimensions in millimetres
Key:
1——graduated measuring cylinder
2——holder with guide-pin
3——guide-bearing
4——anvil (steel)
5——cam
a Height of stroke.
Figure 1 Example of tapping apparatus
5 Sampling
5.1 For the quantities of powder required for each test, see Table 2.
Table 2 Required sample quantities
Apparent density
g/cm3 Cylinder capacity
cm3 Mass of test portion
g
1~4
<1 100
100 100±0.5
50±0.2
>7
>2~7
0.8~2
<0.8 25
25
25
25 100±0.5
50±0.2
20±0.1
10±0.1
5.2 In general, the powder should be tested in the as-received condition. In certain instances, the powder may be dried. However, if the powder is susceptible to oxidation, the drying shall take place in a vacuum or in an inert gas. If the powder contains volatile substances, it shall not be dried.
5.3 The test shall be carried out on three test portions, if possible.
6 Procedure
6.1 Clean the inside wall of the graduated cylinder (4.2) with a suitable clean brush or, if necessary, by rinsing with a solvent, such as acetone. If a solvent is used, thoroughly dry the cylinder before re-use.
6.2 Weigh, to the nearest 0.1 g, the mass of the test portion as indicated in Table 2, using the balance (4.1).
6.3 Pour the test portion into the graduated cylinder. Take care that a level surface of the powder is formed. Place the cylinder in the tapping apparatus (4.3). Tap the cylinder until no further decrease in the volume of the powder takes place (see Note).
Note: In practice, the minimum number of taps, N, would be determined such that no further change in volume takes place. For all further tests on the same type of powder, the cylinder would be subjected to 2N taps, except where general experience and acceptance has established a specific number of taps (no less than N taps) as being satisfactory. For fine refractory metal powders, 3000 taps has been found to be satisfactory for all sizes.
6.4 If the tapped surface is level, read the volume directly. If the tapped surface is not Ievel, determine the tap volume by calculating the mean value between the highest and the lowest reading of the tapped surface. Read the final volume to the nearest 0.5 cm3 when using a 100 cm3 cylinder, and to the nearest 0.2 cm3 when using a 25 cm3 cylinder.
Foreword I
1 Scope
2 Principle
3 Symbols
4 Apparatus
5 Sampling
6 Procedure
7 Expression of results
8 Test report
