RU1788086C - Powdered compound for diffusion saturation of copper alloy products - Google Patents

Abstract

SUMMARY OF THE INVENTION: A powder composition for the diffusion saturation of articles of copper alloys contains, wt.%: Zinc 20-30; copper 15-25; tin 4-8; silicon 3-5; chloride, zinc 3-5; aluminum oxide the rest. Usage: in mechanical engineering to improve performance and recovery of products from copper alloys. The composition provides a reduction in the fragility of the diffusion layer and a decrease in the saturation temperature.

Description

The invention relates to chemical-thermal treatment of copper alloys used in mechanical engineering,

A known composition of the powder mixture for the diffusion saturation of copper and its alloys, containing, wt.%: Zinc 5-15; silicon 10-40; ammonium chloride 0.5-1.5 and refractory clay the rest.

The diffusion layer obtained from this composition is highly brittle, breaks off during mechanical processing, and the saturation process occurs at a relatively high temperature of 800 ° C.

Closest to this purpose is a composition containing, wt.%: Zinc 21-35 Chromium 14-28 Silicon 6-10 Alumina Else The process of diffusion saturation of copper alloys from this mixture has a high productivity (thickness

diffusion layer reaches 1.8-2.0 mm), however, due to the high content of silicon and chlorine, the layer is brittle and skewed. It is machined.

The purpose of the invention is to reduce the brittleness of the diffusion layer, improve its workability, and decrease the temperature of the saturation process.

For this, the powder composition for diffusion saturation of articles made of copper alloys, including zinc, silicon, zinc chloride, alumina, additionally contains copper and tin in the following ratios of components, wt.%: Zinc 20-30 Copper 15-25 Tin 4-8 Silicon 3-5 Zinc chloride 3-5 Alumina Remaining Introduction to the known composition of copper reduces the amount of zinc in the mixture and thereby leads to an increase

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ductility of the diffusion layer (it is known that the zinc content in the Cu-Zn alloy over 30% leads to its sharp embrittlement).

The introduction of tin into the mixture leads to an increase in its content in the diffusion layer, which also contributes to an increase in its ductility (it is known that increasing the tin content to 14% causes an increase in the ductility of the bronze alloy).

For chemical-thermal treatment of products from copper alloys, copper is prepared from PTs-4 zinc powders GOST 12601-76, PME-1 copper powder GOST 4529-75, tin powder PO-E GOST 9723-73, crystalline silicon KP-1 GOST 2169 - 69, zinc chloride (ZnCla) GOST 4529-78, alumina () GOST 8136-76.

Changing the ratio of the components of the saturating mixture in the proposed composition in the direction of increase leads to the formation of dendrides on the surface of the part and deterioration of the surface quality of the parts, a change in the direction of decrease leads to a significant decrease in the thickness of the diffusion layer.

.Example. Samples from bronze of the BROYUSYU brand with a diameter of 20 mm, a height of 12 mm.

Br05Ts5Ts5 with a diameter of 21 mm and a height of 12 mm were subjected to chemical-thermal treatment in the known and proposed powder compositions.

Saturation of the samples was carried out in containers with a fusible seal for 3 hours at a temperature of 680 ° C.

The proposed composition allows to reduce the brittleness of the diffusion layer, to improve its mechanical workability while lowering the temperature during saturation.

Claims (1)

SUMMARY OF THE INVENTION A powder composition for diffusion saturation of articles made of copper alloys containing 1 zinc, silicon, zinc chloride and alumina, characterized in that, in order to reduce the fragility of the diffusion layer and to improve the workability of the products and lower the saturation temperature, it is additionally contains copper and tin in the following ratio of components, wt.%: Zinc 20-30 Copper 15-25, Tin 4-8 Silicon 3-5 Chloride zinc 3-5 Alumina Else.