Powder metallurgically produced component

Abstract

The invention relates to a component produced powder metallurgically in the form of a valve guide or a valve seat ring having an iron-based matrix containing a mineral solid lubricant, with the matrix having a density ranging between 75 and 90% of the theoretical density, and with the mineral solid lubricant having a melting point that lies below the sintering temperature of the matrix and the remaining pore volume of the matrix of the component being melt infiltrated with the solid lubricant.

1 . Component produced powder metallurgically in the form of a valve guide or a valve seat ring having an iron-based matrix containing a mineral solid lubricant, with the matrix having a density ranging between 75 and 90% of the theoretical density, characterized in that the mineral solid lubricant has a melting point that lies below the sintering temperature of the matrix and the remaining pore volume of the matrix of the component is melt infiltrated with said solid lubricant. 
     
     
         2 . Component according to  claim 1 , characterized in that the solid lubricant has a melting point in the range of between >300 and 1600° C., in particular between 450 and 1300° C. 
     
     
         3 . Component according to  claim 1 , characterized in that the solid lubricant comprises two or several salts of alkali and/or alkaline earth metals. 
     
     
         4 . Component according to  claim 1 , characterized in that the solid lubricant contains salts of Li, Na, K, Mg, Ca, Ba and/or Sr. 
     
     
         5 . Component according to  claim 4 , characterized in that the component contains at least two salts selected from the Li, Mg, Ca and Ba salts. 
     
     
         6 . Component according to  claim 1 , characterized in that the solid lubricant consists of the eutectic mixture of two salts. 
     
     
         7 . Component according to  claim 1 , characterized in that the solid lubricant consists of a eutectic mixture of CaF 2 /BaF 2 . 
     
     
         8 . Method for manufacturing a tribological component according to  claim 1  involving the steps
 A1 Provision of the powder mixture for the matrix of the sintered component; 
 A2 Press forming the powder mixture mentioned against A1 into a compact; 
 B1 Provision of powder for the solid lubricant; 
 B2 Press forming the powder mentioned against B1 into a compact; 
 C1 Sintering the compact mentioned against A2 in the presence of, preferably in contact with, the compact mentioned against B2, or alternatively 
 D1 Sintering the compact mentioned against A2 in a first step at a first temperature T 1  and D2 Infiltrating the sintered body mentioned against D1 in the presence of, preferably in contact with, the compact mentioned against B2 in a second step at a second temperature T 2 . 
 
     
     
         9 . Method according to  claim 8 , characterized in that the powder for the compact of solid lubricant has an average grain size of ≤100 μm, and preferably of ≤30 μm. 
     
     
         10 . Method according to  claim 8 , characterized in that the powder mixture for the matrix of the sintered component is pressed to achieve a density of 7.2 g/cm 3 , preferably of between 6.5 and 6.95 g/cm 3 . 
     
     
         11 . Method according to  claim 8 , characterized in that the powder for the solid lubricant is a powder mixture of calcium fluoride and barium fluoride. 
     
     
         12 . Method according to  claim 11 , characterized in that the powder mixture for the solid lubricant consists of 38 wt. % calcium fluoride and 62 wt. % barium fluoride. 
     
     
         13 . Use of compacts of a powder mixture of 38 wt. % of calcium fluoride and 62 wt. % of barium fluoride for the infiltration of valve guides and valve seat rings produced by powder metallurgy.