Copper-based repair alloy and preparation method thereof

Abstract

The invention provides a copper-based repair alloy and a preparation method thereof. The copper-based repair alloy comprises 20% to 70% of Cu, 20% to 70% of Zn, 0 to 5% of Sn, 0.2% to 6% of Si, 0.02%to 5% of Ge, 0.2% to 5% of In, 0.01% to 0.5% of Ce, 0.1% to 2.5% of Al and 0.01% to 0.7% of Y. Except for the main elements including the Cu, the Zn and the Sn, the trace elements are added in the form of intermediate alloys in the preparation process, wherein the Si, the Ge, the In, the Ce and the Al are added in the form of copper-based master alloys, and the Y is added in the form of an Al-Y intermediate alloy. Through inert gas for protection of mixing and smelting, a pelletizing device is used for preparing near-spherical repair particles. 925 silver jewelry prepared by using the copper-based repair alloy has few surface defects, the anti-vulcanization dullness and discoloration performance is good, the requirements for the hardness and white brightness of wax setting are met, and thestrength requirements pull wires and pressing sheets can be met.

Description

technical field [0001] The invention belongs to the technical field of alloys, and in particular relates to a copper-based joint alloy and a preparation method thereof. Background technique [0002] Sterling silver is a kind of precious metal, which is widely used in film, jewelry, art and industry. At the same time, sterling silver has the problems of softness, easy wear and oxidation, so it is widely used in the process of manufacturing silver jewelry and handicrafts limit. In the early days, the British added 7.5% copper to pure silver to prepare sterling silver, and it was widely used. However, due to the poor anti-oxidation and anti-sulfur tarnishing ability of sterling silver, there are many casting defects on the surface. Subsequent research can significantly improve the anti-tarnish and discoloration performance of silver products by adding a certain proportion of rare and precious metals Pd and Pt, but the application is limited due to its high price. With the dev...

AI Technical Summary

Problems solved by technology

However, many tests have shown that in the processing of silver products, the proportion of Cu, Zn, Sn and trace elements in the copper-based joint alloy is not appropriate, and the improper smelting and granulation process will directly cause the quality of silver products to decline, such as excessive Excessive Zn is easy to cause defects such as white spots, hot cracks, inclusions, etc. Excessive Sn is prone to appear more hard and brittle phases and intermetallic compounds to reduce the strength of the alloy. The content of trace elements is too low to have no obvious impact on performance, and the content is too high to cause negative effects

[0003] In the actual process of preparing 925 silver products, improper composition of copper-based jointing alloy and improper preparation process will lead to defects such as looseness and inclusions on the surface of precision cast silver jewelry. Insufficient hardness will lead to stone falling and deformation, and poor mechanical properties will lead to wire breakage or compression. Chipping and other defects seriously affect the apparent quality and subsequent processing, reducing the value of silver products

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