Manufacturing technique of powder metallurgy

Abstract

The manufacturing technique for powder metallurgy of the invention includes the steps of: mixing ceramic powder with binders, fillings or lubricants for casting a body; forming a microwave-absorbent body using molding, extrusion, forging, injection or doctor blade; placing the body into a microwave oven for heating and debinding; placing the half-finished product after debinding in a sintering oven for sintering the debinded half-finished product; and finally obtaining a finished product after sintering and temperature lowering.

What is claimed is:  
     
         1 . A manufacturing technique for powder metallurgy comprising the steps of: mixing ceramic powder with binders, fillings or lubricants for casting a body; forming a microwave-absorbent body using molding, extrusion, forging, injection or doctor blade; placing the body into a microwave oven for heating and debinding; placing the half-finished product after debinding in a sintering oven for sintering the debinded half-finished product; obtaining a finished product after sintering and temperature lowering; and the characteristics thereof are: 
 before the body enters the debinding process, the body is placed in a microwave-absorbent medium, and the body along with the medium are placed in the microwave and debinded with adjusted temperature and time required.    
     
     
         2 . The manufacturing technique for powder metallurgy in accordance with  claim 1 , wherein the half-finished body after debinding or a debinded body acquired from other methods is directly placed in the microwave oven for heating to the sintering temperature, and is put in a sintering oven having reached the sintering temperature for sinetering therein using microwave.  
     
     
         3 . The manufacturing technique for powder metallurgy in accordance with  claim 1 , wherein ceramic microwave-absorbent medium containing the microwave-absorbent body is powder mainly made of carbon, carbide, nitride, nitanate, oxide, sulfide or a compound.  
     
     
         4 . The manufacturing technique for powder metallurgy in accordance with  claim 3 , wherein the carbide is SiC, TiC or WC.  
     
     
         5 . The manufacturing technique for powder metallurgy in accordance with  claim 3 , wherein the nitride is TiN, AlN or Si 3 N 4 .  
     
     
         6 . The manufacturing technique for powder metallurgy in accordance with  claim 3 , wherein the titanate is barium titanate, calcium titanate, strontium titanate or lead titanate.  
     
     
         7 . The manufacturing technique for powder metallurgy in accordance with  claim 3 , wherein the oxide is NiO, CoO, CaMnO 3 , LaMnO 3 , SnO 2 , TiO 2 , MgWO 4 , MgO, NiO, SrTiO 3  or SrZrO 3 , ZrO 2  or CaO.  
     
     
         8 . The manufacturing technique for powder metallurgy in accordance with  claim 3 , wherein the oxide is added with compounds such as Li 2 O, La 2 O 3 , CaO, SrO, TiO 2 , Sb 2 O 5 , Ta 2 O 5  or Cr 2 O 3  or ZnO.  
     
     
         9 . The manufacturing technique for powder metallurgy in accordance with  claim 3 , wherein the sulfide is FeS or MnS.  
     
     
         10 . The manufacturing technique for powder metallurgy in accordance with  claim 3 , wherein the compound is Fe 2 O 3 —MeO.  
     
     
         11 . The manufacturing technique for powder metallurgy in accordance with  claim 3 , wherein the compound is Fe 2 O 3 —MeO, and the Fe 2 O 3  may be mixed with NiO, CoO, MoO, MgO, ZnO, CuO, Li 2 O, CaO, FeO, B 2 O, PbO, SrO, La 2 O 3 , Cr 2 O 3 , SnO 2  or WO 3 .  
     
     
         12 . The manufacturing technique for powder metallurgy in accordance with  claim 3 , wherein the NiO, CoO, MoO, MgO, ZnO, CuO, Li 2 O, CaO, FeO, B 2 O, PbO, SrO, La 2 O 3 , Cr 2 O 3 , SnO 2  or WO 3  may be used independently or mixed with others.  
     
     
         13 . The manufacturing technique for powder metallurgy in accordance with  claim 3 , wherein ceramic microwave-absorbent medium containing the microwave-absorbent body may be compounds with any compound ratios from carbon, carbide, nitride, titanate, oxide, sulfide or a compound.  
     
     
         14 . The manufacturing technique for powder metallurgy in accordance with  claim 1 , wherein the non microwave-absorbent medium is a compound having any compound ratio from Al 2 O 3 , SiO 2  or ZrO.  
     
     
         15 . The manufacturing technique for powder metallurgy in accordance with  claim 1 , wherein the macromolecules are binders, fillings or lubricant containing any from acrylic, ethyl cellulose, hydroxypropyl cellulose, polypropylene, polyacetal polymer, ethylene vinyl acetate, atactic polypropylene, styrene-butadienecoplymer, methylcellulose, polyethylene, oxidized polyethylene, cellulose acetate, nylon, polystyrenes, polybutylene, polysulfone, polyethylene, paraffin, wax, mineral oil, vegetable oil, fatty acid, fatty alcohols, fatty ester hydrocarbon wax, epoxy, polyphenylene, phenol, stearic acid, ester wax, oleic acid, diethyl phthalate, and formaldehyde.