SU1222417A1 - Method of producing metallic granules - Google Patents

Description

The invention relates to powder metallurgy, in particular to methods of producing metal melt granules.

The purpose of the invention is to show the best and shorten the duration of the technological cycle. .

The method consists in passing the molten metal through a series of holes with a diameter of 1-8 mm and then cooling the formed granules in a liquid. In this case, an overpressure of 0.01-1 atm is created in the chamber under the melt.

The drawing shows an apparatus 15 for carrying out the proposed method.

The working chamber 1 through the nozzle 2 is filled with inert gas, such as argon, to a pressure of 0.01-1 atm 20 Bbmie atmospheric. After that, the molten metal is poured into the crucible 3 (the level in the crucible is kept constant throughout the process). The metal under its own weight flows out into the chamber through the holes 4 in the bottom of the crucible, the diameter of which is 1-8 mm. Under the action of surface tension forces, the metal jet spontaneously disintegrates into separate droplets, which fall into the tank 5 with the cooling liquid 6, where they solidify to form granules. The granules are accumulated in collection 7.

The size of the granules is regulated by changing the diameter of the holes, the gas pressure under the melt, the temperature of the metal and the height of its column in the crucible. In this case, the formation of granules occurs only 35

40

to at the indicated pressure and hole diameter. When the differential pressure

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If the pressure is less than 1 atm and the diameter of the holes is less than 1 mm, the metal does not flow out of the crucible, whereas if the pressure drops below 0.01 atm and the diameter of the holes is more than 8 mm, there is a jet flow without the formation of granules.

Example 1. Receive granules from an alloy of rare earth elements based on cerium (iron content 17%, magnesium 1.5%). The melt temperature is 960tlO ° C, and its height in the working crucible for REM is 16–18 cm, which corresponds to a melt column pressure of 0.096–0.108 atm (a rare-earth metal mass based on cerium 6.0 g / cm). The conditions of the experiments and the results are shown in Table. 1 and 2.

Example 2. Get granules V96ts and AD1 based on aluminum. The temperature of the melt is 900110 ° C, and its height in the working crucible for V96ts and AD1 alloys is 18-20 cm, which corresponds to the following pressure of the melt column, atm: for alloy V96ts (density 3 g / cm) 0.054-0.060; for alloy AD1 (density 2.7 g / cm) 0.048-0.054.

The data on the effect of the pressure drop and the diameter of the holes on the granulation are given in Table. one.

The data on the effect of excess pressure on the yield and duration of the technological cycle are given in Table. 2, and the average yield value is given for lattice cells in the range of 1–8 mm.

Thus, the proposed method allows to increase the yield and reduce the time of the technological cycle in obtaining pellets from metals and alloys.

Table 1

Note: 1- no expiration.

2- jet discharge is observed.

3- granulation process occurs.

Continued table. one,

Compiled by V. Kazan Editor I. Derbak Tehred M. Morgental - Proofreader. G. Reshetnik

Order 1646/11 Circulation 757Subscription

VNIIPI USSR State Committee

for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5

Filial PPP Patent, g, Uzhgorod, st. Project, 4

.

Strong gas saturation, waste, and in addition, in the case of strong gas saturation, the granules from rare-earth metals completely decompose into oxides within 50 days.

Claims (1)

METHOD FOR PRODUCING METAL GRANULES, including passing molten metal through holes at a pressure drop and subsequent cooling, characterized in that, in order to increase the yield and reduce the duration of the process cycle, the molten metal is passed through holes with a diameter of 1-8 mm, and a pressure drop is created inert gas under the melt is 0.01-1 atm above atmospheric. SU., „1222417