Process for producing components composed of titanium or titanium alloy by means of mim technology

Abstract

The present invention relates to a process for producing a component composed of titanium or titanium alloy by means of MIM technology. In this process, a homogeneous mixture of boron powder having a particle size of less than 10 μm, preferably less than 5 μm, more preferably less than 2 μm, and titanium powder and/or titanium alloy powder is produced, and binder is mixed with the homogeneous mixture of boron and titanium powder and/or titanium alloy powder and also, if appropriate, an additive in a kneader, the mixture is moulded by injection moulding to produce a green part, the moulded composition is subjected to chemical and/or thermal removal of binder to produce a brown part and the composition from which the binder has been removed is sintered at a temperature in the range from 1000° C. to 1600° C.

1 . Process for producing a component composed of titanium or titanium alloy, comprising:
 (a) mixing a boron powder having a particle size of less than 10 μm and titanium powder and/or titanium alloy powder to produce a homogeneous boron powder with titanium powder and/or titanium alloy powder,   (b) mixing a binder with the homogeneous mixture of boron and titanium powder and/or titanium alloy powder and, optionally, an additive, in a kneader,   (c) molding the mixture of (b) by injection molding to produce a green part,   (d) subjecting the green part to chemical and/or thermal removal of the binder to produce a brown part, and   (e) sintering the brown part at a temperature in the range from 1000° C. to 1600° C.   
     
     
         2 . Process according to  claim 1 , wherein the amount of boron powder is selected so that from 0.05% by weight to 1.5% by weight of boron is present in the component, based on the weight of the component after sintering. 
     
     
         3 . Process according to  claim 2 , wherein the boron content is in the range from 0.1% by weight to 1.0% by weight. 
     
     
         4 . Process according to  claim 1 , wherein the sintering temperature is in the range from 1300° C. to 1450° C. 
     
     
         5 . Process according to  claim 1 , wherein the mixing of boron powder and titanium powder and/or titanium alloy powder takes place under a protective gas atmosphere. 
     
     
         6 . Process according to  claim 1 , wherein the mixing of binder with the homogeneous mixture of boron powder and titanium powder and/or titanium alloy powder takes place under a protective gas atmosphere. 
     
     
         7 . Process according to  claim 5 , wherein the protective gas is argon or helium. 
     
     
         8 . Process according to  claim 1 , wherein sintering takes place in a vacuum. 
     
     
         9 . Process according to  claim 1 , wherein the sintered components have an oxygen content of less than 0.3% by weight, determined by melt extraction analysis. 
     
     
         10 . Process according to  claim 1 , wherein the titanium powder and/or titanium alloy powder has a particle size of less than 45 μm. 
     
     
         11 . Process according to  claim 1 , wherein TiAl 6 V 4  is used as titanium alloy powder. 
     
     
         12 . Process according to  claim 11 , wherein gas-atomized TiAl 6 V 4  is used. 
     
     
         13 . Process according to  claim 1 , wherein the binder is selected from the group consisting of thermoplastic or thermoset polymers, thermogelling substances, waxes and surface-active substances and mixtures thereof. 
     
     
         14 . Process according to claim wherein the green part is, in step (d), subjected to chemical binder removal in a hydrocarbon, to produce a brown part. 
     
     
         15 . A component composed of titanium or titanium alloy, produced by the process of  claim 1 . 
     
     
         16 . Process according to  claim 6 , wherein the protective gas is argon or helium. 
     
     
         17 . Process according to  claim 14 , wherein the hydrocarbon is hexane or heptanes. 
     
     
         18 . A component composed of titanium or titanium allow produced by the process of  claim 2 . 
     
     
         19 . The component of  claim 15 , wherein the component is composed of a titanium alloy. 
     
     
         20 . The component of  claim 19 , wherein the titanium alloy is TiAl 6 V 4 .