Preparing method of iron-based molding mixture

Abstract

The invention discloses a preparing method of an iron-based molding mixture. The method comprises following steps: raw materials are weighed; iron powder, copper powder, graphite, a liquid bonding agent and a lubricating agent are weighed according to the formula requirement; the iron powder is wetted; the liquid bonding agent is added into the iron powder for standing for 20 min to 200 min, and wetted iron powder is formed; in the mixing process, the wetted iron powder, the graphite and the lubricating agent are put into a mixing machine, and sufficient mixing is carried out; the copper powder is added into the mixing machine, after sufficient mixing, the copper powder is taken out, and the mixture is obtained. According to the method, the bonding agent is sufficiently wetted with the iron powder to form the wetted iron powder, the graphite is easily bonded with the wetted iron powder, the segregation degree of the graphite can be reduced, particularly for the condition that the wetted iron powder is added into the mixing machine to be sufficiently mixed, and then graphite is added, the graphite surface is dried, a bonding agent film is arranged on the surface of the iron powder, and the iron powder and the bonding agent film are combined more easily.

Description

technical field [0001] The invention belongs to the field of iron-based molding mixture, and in particular relates to a preparation method of iron-based molding mixture. Background technique [0002] Powder metallurgy technology is a technology that has the characteristics of material saving, energy saving, low cost, and can be molded in large quantities to form parts with near-net shape and dimensional accuracy. Its products are widely used in machinery, aviation, especially automobiles, motorcycles and home appliances. It has been widely used in the industry. With the progress of society and the intensification of competition among powder metallurgy products enterprises, the requirements for product performance are getting higher and higher; to improve product performance, uniform powder composition is the key; only a mixture with uniform composition can produce high-quality products. It is also conducive to the automatic production of powder metallurgy products, thereby ...

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Problems solved by technology

[0003] Copper powder is one of the most common alloy powders added to iron-based mixtures. The range of copper powder added is relatively large. For example, the iron-based material disclosed in the Chinese patent document with application number CN200510037939.6 has a copper content of 1-3%. , and the application number is CN201310415059.2 Chinese patent literature discloses the iron-based material, the copper content is 16-18%; for the mixture containing no copper or less copper, the segregation problem of graphite is easier to solve, but for the mixture containing Mixtures with more copper (generally referring to copper greater than 3wt%) are more difficult to solve. For example, the Chinese patent literature with application number 201110048677.9 points out that developed countries such as Japan, Sweden, and the United States have successively developed non-segregation bonding powders. , such as introducing a liquid binder to bond low specific gravity additives, such as graphite and lubricants, but the bonding effect for high specific gravity additives such as copper powder or nickel powder is limited; the Chinese patent document with application number 00121777.1 discloses a kind of iron- Graphite composite powders, provided that the composite powder mixture contains less than about 3% copper

Of course, reducing the degree of graphite segregation can be improved by increasing the amount of binder, but increasing the amount of binder will make the process performance of the mixture worse, such as fluidity

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