One, overview
Powder metallurgy is the preparation of metal or metal powder (or a mixture of metal and non metal powder) as raw material, after forming and sintering, the manufacture of metal materials, products of various types of composite and process technology. Powder metallurgy method are similar, and the production of ceramic therefore, a series of powder metallurgy new technology can also be used in the preparation of ceramic materials. Because of the advantages of powder metallurgical technology, it has become the new materials of keys, play a decisive role in the development of new materials.
Current situation and development prospect of powder metallurgy.
Powder metallurgy industry in China has gone through nearly 10 years of rapid development, but with foreign industry still exists in the following aspects: (1) the gap between enterprises, small scale, economic and foreign enterprises vary greatly. (2) cross product, enterprise mutual suppression of prices, competition is unusually intense. Two, characteristics Powder metallurgy has the chemical composition and mechanical, unique physical properties, and these properties cannot be obtained by traditional methods of casting. Can be directly made into porous, semi dense or fully dense materials and products by powder metallurgy technique, such as bearing, gear, cam, a guide rod, tool, is a less or no cutting process. (1) powder metallurgical technology can minimize the alloy composition segregation, eliminate the thick, uneven casting organization.
In the preparation of high performance rare earth permanent magnetic materials, rare earth hydrogen storage materials, rare earth luminescent materials, rare earth catalyst, high temperature superconducting materials, a new metal material (such as Al-Li alloy, heat resistant Al alloy, super alloy, powder, stainless steel powder high speed steel, intermetallic compounds for high temperature structural materials) plays an important role in.
(2) can be prepared amorphous, microcrystalline, quasicrystals, nanocrystalline and supersaturated solid solution and a series of high performance non equilibrium materials, these materials with electrical, magnetic, optical and mechanical properties.
(3) can easily realize multiple types of composite, give full play to the characteristics of each element of the respective materials, is a technology to produce high performance metal matrix and ceramic composite materials with low cost. (3) can easily realize multiple types of composite, give full play to the characteristics of each element of the respective materials, is a technology to produce high performance metal matrix and ceramic composite materials with low cost.
(4) can be materials and products with special structure and properties the production of ordinary melting method can not produce, such as new porous biomaterials, porous membrane materials, high performance structural ceramic products and ceramic materials etc.. (5) can achieve near net shape forming and automation of production, thus, can effectively reduce the production of resources and energy consumption.
(6) can make full use of ores, tailings, steelmaking sludge, mill scale, recycling scrap metal as raw material, is a new technology of material can be effective regeneration and comprehensive utilization.
Our common machine tools, hardware tools, is a lot of powder metallurgy technology.
The production process of three, powder metallurgy
(1) the production of powder.
(1) the production of powder.
The production process includes the steps of powder mixed powder preparation, powder..
For molding and plasticity improve powder is usually added to gasoline, rubber or paraffin, plasticizer.
(2) pressing. Powder under the pressure of 500~600MPa, pressed into required shape. (3) sintering.
High temperature furnace and vacuum furnace with protective atmosphere. High temperature furnace and vacuum furnace with protective atmosphere.
Sintering is different from the metal melting, sintering at least one element is still in the solid state. The sintering process of powder particles by diffusion, recrystallization, welding, chemical dissolution, a series of physical chemical processes, become a metallurgical products with certain porosity. (4) after treatment. In general, good sintering parts can be used directly.
But for certain size requirements of high precision and high hardness, wear resistance of the parts and sintering processing. After treatment including press, rolling, extrusion, quenching, quenching, oil, and infiltration. After treatment including press, rolling, extrusion, quenching, quenching, oil, and infiltration. Four, powder metallurgy material application and classification
(1) application: (car, motorcycle, textile machinery, industrial sewing machine, electric tools, hardware tools, electrical appliances. Mechanical Engineering) and other powder metallurgy parts (Tie Tongji).
(2) classification: metallurgical powder material, powder metallurgy antifriction material, powder metallurgy friction materials, powder metallurgy structural parts, powder metallurgy mould material, magnetic material and powder metallurgy and powder metallurgy high temperature materials etc..
Five, powder metallurgy technology and performance of gold
Isostatic compaction in powder metallurgy
Powder metallurgy metal injection molding
Powder metallurgy metal injection molding
Powder forging powder metallurgy
Pressure sintering powder metallurgy
The properties of powder (property of powder)
In general all the properties of powder. It includes: geometric properties of powder (particle size, specific surface, pore size and shape); chemical properties of powder (chemical composition, purity, oxygen content and acid insoluble powder); mechanical properties (bulk density, flowability, formability, compression and shear angle, angle of repose); physical properties and surface properties of the powder (true density, gloss, microwave absorption, surface activity, ze%26mdash; ta (%26ccedil;) |
