SU1291285A1 - Method of pressing articles from metal powders - Google Patents

Description

The invention relates to powder metallurgy, in particular to methods for the isostatic pressing of powder articles.

The purpose of the invention is to improve the uniformity of the properties of the products in the radial direction.

The method is carried out as follows.

Titanium powders are poured into a capsule of titanium in the following order: in the center of the fraction - 180 microns, in the next layer from the center of the fraction - 500-315 microns, in the next layer +1000 microns, in the next layer - 1000-630 microns, then - 630-500 microns, then - 500-315 microns, on the outer surface of products - 315 + 180 microns. Powder billet with this layer-by-layer filling of powder is heated to 900 C

The data indicate a higher density stability throughout the volume obtained by the proposed method of the product. Changing the thickness of the layers of the filling of the proposed method does not lead to a violation of the stability of the properties by volume of the resulting product (table 2). The displacement of the layer with the maximum particle size from the intermediate position towards the periphery or toward the center also does not significantly affect the density stability by volume of the resulting product (Tables 2 and 3). The dispersion of particle sizes also does not affect the distribution and is subjected to an isostatic pressure of 100 MPa. As a result of the coining process, a cylindrical product is obtained with an appropriate distribution of properties by volume of the resulting density and properties in the radial section.

board (table 1 and 2). Thus, the implementation of the pre vla table 3 shows the distribution of the method allows the liquidity of the density depending on the location of the marriage of products due to the variation of dense layers with the largest and smallest in cross section.

Table I

The current limit is the fraction of the backfill, µm -180 -500 + 315 +1000 -) 000-630 -630 + 500 -500 + 315 -315 + 180

Layer thickness mm 33 3 3 333

Relative

density, X 99.60 99.70 99.65 99.60 99.60 99.60 99.60

O

five

0

particle size, in table 4 - distribution of density depending on the particle size of powders and titanium granules.

The density of the products when filling the powder in layers by a known method for titanium granules is given in table.5.

The data indicate a higher density stability throughout the volume obtained by the proposed method of the product. Changing the thickness of the layers of the filling of the proposed method does not lead to a violation of the stability of the properties by volume of the resulting product (table 2). The displacement of the layer with the maximum particle size from the intermediate position towards the periphery or toward the center also does not significantly affect the density stability by volume of the resulting product (Tables 2 and 3). The scatter of particle sizes also does not affect the distribution of properties over the volume of the resulting product.

table 2

Thickness is 1, mm 2020

Relative

density,% 99.60 99.65 99.65 99.60 99.60 99.60 99.60

Layer thickness mm 20 Fractions 20

20

20 20 20 20 -180 +1000 -1000 + 630 -630 + 500 -500 + AOO -400 + 315 -315 + 180

Relative

density D99.60 99,6599,6599,6099,60 99,60 99,60

The fraction of the backfill, mkm-180 -315 + 180 -630 + 315 +1000 -1000 + 500-500 + 315-315 + 180

Awesome

density, Z99,60 99,6599,7099,6599,65 99,60 99,60

Fractions, backfillings, mkm -180 -3000 + 1000-5000 + 3000 - ЗбОО + 1000 -1000 + 500 -300 + 315 -315 + 180

Layer layer, mm 5 5

Relative density, /: 99.55 99.65

Backfill layer, mm 20 20

. five

99.70 99.70 99.70 99.65 99.65

20

20

20

20

20

Relative density,% 99.45 99.50 99.65 99.65 99.63 99.60 99.55

Continuation of table 2

20

20

20

20

Table 3

20

-31

Table

. five

20

20

20

20

Diameter of granules, mm

Relative density. X

3.0 3.2 3.4 3.6 3.8 4.0 4.2

96.2 98.0 99.6 99.1 98.0 97.0 96.4

Table 5

Claims (1)

METHOD FOR PRESSING PRODUCTS FROM METAL POWDERS, including layer-by-layer filling of granules into the shell and isostatic compaction, characterized in that, in order to increase the uniformity of the properties of products in the radial direction, filling is carried out by. the location of the granules in layers over the radial section of the shell with an increase in their diameter from the center and from the outer surface of the product, while the diameter of the particles located in the center is less than the diameter of the particles located on the outer surface. ё с ё Q0 Joint venture