1, the vast majority of refractory metals and their compounds, false alloys, porous materials can only be manufactured by powder metallurgy method.
2, because the powder metallurgy method can be pressed into the final size of the compaction, without or little need for subsequent mechanical processing, it can greatly save metal, reduce product costs.The loss of metal in the manufacture of products by the powder metallurgy method is only 1-5%, while the loss of metal in the production of products by the ordinary casting method may be as high as 80%.
3, because the powder metallurgy process in the material production process does not melt the material, it is not afraid of mixing with the impurities brought by the crucible and deoxidizer, and sintering is generally carried out in vacuum and reducing atmosphere, not afraid of oxidation, and will not give any pollution to the material, it is possible to make high purity materials.
4, powder metallurgy method can ensure the correctness and uniformity of the material composition ratio.5, powder metallurgy is suitable for the production of the same shape and a large number of products, especially gear and other high processing costs of products, with powder metallurgy manufacturing can greatly reduce the production cost.
1, the preparation of raw material powder.Existing pulverizing methods can be roughly divided into two categories: mechanical and physico-chemical.The mechanical method can be divided into: mechanical crushing and atomization method;Physical and chemical methods are further divided into electrochemical corrosion method, reduction method, chemical method, reduction-chemical method, vapor deposition method, liquid deposition method and electrolysis method.The most widely used methods are reduction, atomization and electrolysis.
2. Powder forming to the desired shape of the blank block.The purpose of molding is to make a certain shape and size of the compact, and make it have a certain density and strength.The molding method is basically divided into pressure molding and non - pressure molding.Pressure molding is the most widely used molding.
3. Sintering of billet.Sintering is a key process in powder metallurgy.The final physical and mechanical properties are obtained by sintering the compacted blank after forming.Sintering is divided into unit sintering and multi - component sintering.The sintering temperature is lower than the melting point of the metal and alloy used for the solid phase sintering of the unit system and multi-component system.For the liquid phase sintering of the multi-component system, the sintering temperature is generally lower than the melting point of the refractory component, but higher than the melting point of the fusible component.In addition to ordinary sintering, there are loose sintering, melt leaching method, hot pressing method and other special sintering processes.
4. Post-sequence processing of products.The treatment after sintering can be adopted in a variety of ways according to the different requirements of the product.Such as finishing, immersion, machining, heat treatment and electroplating.In addition, in recent years, some new processes such as rolling and forging have also been applied to the processing of powder metallurgy materials after sintering, and achieved better results.
1, representative of the iron-based alloy, will be large volume of precision products, high quality structural parts development.
2. Manufacture high performance alloy with uniform microstructure, difficult processing and complete density.
3. Special alloys, generally consisting of mixed phases, are manufactured by an enhanced densification process.
4, manufacturing heterogeneous materials, amorphous, microcrystalline or metastable alloy.
5, processing unique and non-general form or composition of composite parts.
1, can process special materials.Material powder metallurgy methods can produce refractory metals as well as compounds, pseudo alloys, and porous materials.
2, save metal, reduce costs.Because powder metallurgy can be pressed into the final size of the compaction, there is no need to use mechanical processing.The loss of metal produced this way is only 1 to 5 percent, compared with 80 percent for normal processing.
1, high quality structural parts: powder metallurgy is representative of the iron-based alloy, will be developed to large volume of precision products, high quality structural parts.
2, high performance alloy: powder metallurgy manufacturing has uniform microstructure structure, processing is difficult and completely dense high performance alloy.
3, mixed phase special alloy: powder metallurgy with enhanced densification process to manufacture general special alloy containing mixed phase composition.
4, composite parts: processing unique and non-general form or composition of composite parts.
5. Preparation of high purity materials.Powder metallurgy process in the material production process does not melt the material, it will not be mixed with other substances brought by impurities, and sintering is carried out in vacuum and reducing atmosphere, not afraid of oxidation and there will be no pollution of the material.Therefore, the purity of the product is relatively high.
6, Correctness of material distribution.Powder metallurgy method can ensure the correctness and uniformity of material composition in the proportion.
7, mass production to reduce costs.Powder metallurgy is suitable for the production of products with a large number of uniform shapes, such as gear and other products with high cost, which can greatly reduce the production cost.