Preparation method of fine metal powder coarsening

Abstract

The invention belongs to the technical field of pretreatment before metal powder is pressed and formed, and relates to a preparation method of fine metal powder coarsening. The method comprises the steps that firstly, all components of dry powder are uniformly mixed in proportion, so as to obtain loose fine powder, and then the loose fine powder obtained in the previous step is pressed by adopting a press and a mold, so as to obtain pressed powder; then the pressed powder is ground into large particles first, and then fine grinding and smashing are performed, so as to obtain smashed powder particles; and finally, the smashed powder particles are screened by adopting a screening machine according to the particle size. The preparation method has the advantages of simple process and convenience in operation, a middle mold can be filled with the formed powder smoothly, the weight consistency is good, the pressing is facilitated, the loss of the pressing mold can be reduced, the service life of the mold can be prolonged, additionally, the size and precision of a product are increased, the particles are not liable to break and are convenient to transport and store, dust and pollution are reduced, and the preparation method is especially suitable for powder with high surface activity at room temperature.

Description

Technical field: [0001] The invention belongs to the technical field of pretreatment before metal powder pressing and forming, and relates to a preparation method for coarsening metal fine powder. Background technique: [0002] Powder metallurgy is a material-saving, energy-saving, quick-acting, non-polluting, and less-cutting, no-cutting, high-efficiency metal forming process suitable for mass production. It is also an important technology for manufacturing special metal materials. Powder metallurgy can be used in different processes , Consolidate various powdered single-element metals or alloys into near-net shape or final shape parts, and then sinter in a protective atmosphere at a temperature lower than the melting point of the main metal component, through the metallurgical bonding between powder particles, endow Part materials are based on mechanical strength and various physical properties. The consolidation method is mainly press forming. The purpose of forming is to...

AI Technical Summary

Problems solved by technology

Now the ideal way is to coarsen the fine powder to 80μm~150μm. This kind of coarsened powder has the characteristics of large surface energy, easy shrinkage and high density of fine powder during sintering, and it is easy to add other elements. Advantages, while avoiding the problem of mold jamming caused by too fine powder, the more common method to obtain coarser fine powder is: first mix the powder to make the ball particles larger, and add a binder when the powder is mixed. It brings new problems. To eliminate the binder added to the powder (usually called "dewaxing"), some new processes need to be added to eliminate the binder. The purpose of roughening through the binder has the following disadvantages : First, the binder not only increases consumables and costs, but also tends to cause sintering atmosphere problems; second, the binder achieves dewaxing through high temperature or oxidation, which is easy to pollute the environment or the furnace; third, often reduces material sintering Density after sintering, resulting in reduced mechanical strength after sintering

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