SU1675041A1 - Method of die casting of composite metal products - Google Patents

Abstract

The invention relates to casting and can be used to produce products with enhanced resistance to vibrations with an aluminum-based alloy matrix, for example, electric motor bearing shields. The purpose of the invention is to increase the resistance of products to vibration loads. The method involves using high-damping copper-manganese-based alloy as a reinforcing element with direct and reverse martensitic transformation in the form of shattered and cold-worked chips, introducing it into the molten aluminum-based alloy before pouring into the mold in the amount of 5-25% mass of the melt, bringing its temperature to the moment of pouring up to 680 750 ° C, removing the casting at 500-400 ° C and maintaining air cooling.

Description

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The invention relates to casting and can be used to produce products with enhanced resistance to vibrations with an aluminum-based alloy matrix, for example, electric motor bearing shields.

The purpose of the invention is to increase the resistance of products to vibration loads.

To this end, composite castings reinforced with deformed elements are made by injection molding. In the manufacture of the matrix material, the casting is crystallized in a mold under pressure, removed from the mold and cooled.

As reinforcing deformed elements, use is made of crushed and naklepannaya chips from hardened high damping alloy based on copper-manganese with direct and reverse martensitic transformation, and becoming aluminum-based as a matrix material. The chips are introduced into the melt of the matrix material before pouring into the mold in the amount of 5-25% by weight of the melt. By the time of pouring, the melt temperature is adjusted to 680-750 ° C. The casting is removed from the mold at 500-400 ° C and cooled in air.

The resistance to vibrations of a product made by the method described above is increased compared with a similar cast aluminum product, since the matrix is reinforced with elements from an alloy that is in a state where it has good damping properties. The use of reinforcing elements hardened from the temperature range of stability of the high-temperature phase of the copper-manganese alloy as a material

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furthermore, the development of reverse and direct martensitic transformations during subsequent heating and cooling, producing a martensitic structure in the alloy, which is associated with a high damping capacity. The lamellar form and the rough surface of the elements in the form of crushed and riveted chips improves the connection between the elements and the die. Introduction of a melt of elements in an amount of less than 5% by weight of the melt does not provide a significant improvement in damping.

If the elements are introduced into the melt in an amount of more than 25%, then cracks appear in the casting. When the temperature of the melt with elements below 680 ° C, the mold is not completely filled, if the temperature of the melt is above 75 (HZ - cracks appear cracks. both in the region of 500-350 ° C and at 300-150 ° C. The first processes provide high damping properties of the copper-manganese-based alloy, and the latter increase the stability of the damping properties in the alloy curing process at climatic temperatures, the damping properties of alloys based on copper-marg and nets and the resulting composite products are retained when heating up to 100-150 ° C. The proposed method allows combining the process of casting aluminum-based alloys with reinforcement with elements of an alloy based on the copper-manganese provide high damping properties of these elements.

The proposed method semitones bearing shields for electric motors. For reinforcement, a copper-manganese alloy containing 50% Mn, melted in an induction furnace and hardened from 850 ° C to water, is used. The shavings obtained on a lathe and crushed in a steel mortar. With the introduction of reinforcing elements into the melt, they are rapidly heated to 680-750 ° C. As a result, the growth of manganese particles is suppressed. In addition, in a plastically deformed Cn-Mp alloy, the decomposition of the supercooled high-temperature phase is slowed down, which also contributes to the grinding of manganese a particles and

achieve better damping performance. In electric motors with bearing shields made of unreinforced alloy AK5M2, the relative magnitude of the movements during vibrations was taken as 100%.

When reinforcing alloy AK5M2 5 wt.% 2 vol.%) And 25 wt.% (-12 vol.%), The corresponding displacements are 70 and 45%. In the case of reinforcement 2 wt.%, The displacement amount is 97%, and reinforcement 30

wt.% leads to cracks in the castings.

Thus, the use of reinforced cast bearing shields reduces vibrations of electric motors by 1.5–2 times and improves their operating conditions.

Claims (1)

The proposed method makes it possible to use chips for copper-manganese-based alloys as a material for reinforcement, which is a waste of mechanical processing of parts made from such alloys, it is simple, technological, and does not require special foundry equipment. The invention The method of manufacture by injection of composite castings, reinforced by deformed elements, by casting, including crystallization of the matrix material in a mold under pressure, extraction and cooling, is also characterized by the fact that, in order to increase the resistance of products to vibration loads, an alloy on the basis of aluminum, and as the reinforcing deformed elements — crushed and peeled chips from a hardened high-alloy copper-manganese-based alloy with direct and reverse martensitic transformation, while introducing it into the molten matrix material before pouring into the mold in an amount of 5-25% by weight of the melt with the increase of its temperature by the time of pouring up to 680- 750 ° C, the casting is removed at 500 - 400 ° C, and cooling lead to air