SU960291A1 - Modifier for treating aluminium casting alloys - Google Patents

Description

10-30

Sodium Fluoride Ostg. Hexachloroethane

OTOpHCTfcjfl sodium is a eutectic modifier and degasser. A reduced amount of potassium fluoroborate while reducing the cost of the modifier does not give the effect of remodification (an increased amount of boron gives large crystallization centers, which leads to an increase in the size of aluminum aendrites).

Potassium chloride, which is introduced in an increased amount along with sodium fluoride, forms a low-melting mixture, which quickly melts when mixed into the melt and prevents metal oxidation, helps to ensure active mass transfer between the melt and the salt mixture, causing a more complete transition from the mixture to the sodium and boron melt , and removing from the melt the aluminum oxides formed by the reaction of the mixture with the liquid melt.

Experimental work was carried out to determine the optimal composition.

The results of the experiments are given in the table.

ten

ten

70

ten

20

27.5

32.5

20

thirty

15

35

20

13

34

18

25

17

33

20

thirty

12

thirty

13

35

Weak shredding of the dendrites due to the fracture of the primary casting and there is no eutectic

Good grinding of primary A1 and S I dendrites and eutectics

A small amount of OXID films in the fracture of castings

There are no oxide films in the fracture of castings.

Good effect of modification, a significant increase in alloy stifling

Reducing the effect of modification with a simultaneous increase in the metal content in the slag

The table shows that the best grinding of the primary aluminum dendrites and the absence of oxide films in castings is achieved using a modifier containing, wt.%

Potassium chloride27.5

Fluoroborate potassium 32.5

Sodium fluoride 20,0

Hexachloroethane .. 20.0

This modifier was carried out. modification of the alloy AL-4. The temperature of processing and casting of the alloy is 740-760 ° C. From this alloy, casting of a drive axle is cast by casting into a chill mold. The modifier consumption is 0.5% by weight of the metal,

The use of the proposed modifier makes it possible to improve the quality of parts made of alloy AL-4, to use a cheaper modifier for the manufacture of castings.

Claims (2)

1.Rutman M.M. et al. Boron and titanium assimilation and magnesia loss during the development of silumins by boron salts. In Coll. Modern non-ferrous alloys and progressive casting methods. M., 1974, p. 137-142, 2. Authors certificate of the USSR 582315, cl. C 22 C 1/06, 1976.