Cemented carbide containing tungsten carbide and iron alloy binder

Abstract

A sintered cemented carbide body including tungsten carbide, and a substantially cobalt-free binder including an iron-based alloy sintered with the tungsten carbide. The iron-based alloy is approximately 2-25% of the overall weight percentage of the sintered tungsten carbide and iron-based alloy. The tungsten carbide may be approximately 90 wt % and the iron-based alloy may be approximately 10 wt % of the overall weight percentage of the sintered tungsten carbide and iron-based alloy. The tungsten carbide may comprise a substantially same size before and after undergoing sintering. The iron-based alloy may be sintered with the tungsten carbide using a uniaxial hot pressing process, a spark plasma sintering process, or a pressureless sintering process. The sintered tungsten carbide and iron-based alloy has a hardness value of at least 15 GPa and a fracture toughness value of at least 11 MPa√m.

What is claimed is: 
     
         1 . A sintered cemented carbide body comprising:
 tungsten carbide; and   a substantially cobalt-free binder comprising an iron-based alloy sintered as a matrix with/around the tungsten carbide particles throughout the body,   wherein the sintered tungsten carbide and iron-based alloy comprises a hardness value of at least 15 GPa.   
     
     
         2 . The sintered cemented carbide body of  claim 1 , wherein the iron-based alloy is between 0% and 49.999% of the overall weight percentage of the sintered tungsten carbide and iron-based alloy. 
     
     
         3 . The sintered cemented carbide body of  claim 1 , wherein the tungsten carbide comprises approximately 90 wt % and the iron-based alloy comprises approximately 10 wt % of the overall weight percentage of the sintered tungsten carbide and iron-based alloy. 
     
     
         4 . The sintered cemented carbide body of  claim 1 , wherein the tungsten carbide comprises a substantially same size before and after undergoing sintering. 
     
     
         5 . The sintered cemented carbide body of  claim 1 , wherein the sintered tungsten carbide and iron-based alloy comprises a fracture toughness value of at least 11 MPa√m. 
     
     
         6 . The sintered cemented carbide body of  claim 1 , wherein the iron-based alloy comprises a solid solution phase without a graphite or M 6 C phase. 
     
     
         7 . The sintered cemented carbide body of  claim 1 , wherein the iron-based alloy binder comprises an element that forms a grain-refining carbide (e.g., Zr leads to ZrC, V leads to VC). 
     
     
         8 . The sintered cemented carbide body of  claim 1 , wherein the tungsten carbide comprises a microparticle size of approximately 0.5-20 μm. 
     
     
         9 . The sintered cemented carbide body of  claim 1 , wherein the substantially cobalt-free binder comprises no more than 0.2 mass % of cobalt. 
     
     
         10 . (canceled) 
     
     
         11 . A method of forming a tungsten carbide cemented body, the method comprising:
 providing tungsten carbide; and   sintering a substantially cobalt-free binder comprising an iron-based alloy binder with the tungsten carbide to form the cemented tungsten carbide body,   wherein the sintered tungsten carbide and iron-based alloy comprises a hardness value of at least 15 GPa and a fracture toughness value of at least 11 MPa√m.   
     
     
         12 . The method of  claim 11 , wherein the sintering comprises a uniaxial hot pressing process. 
     
     
         13 . The method of  claim 11 , wherein the sintering comprises a field assisted sintering technology process. 
     
     
         14 . The method of  claim 11 , wherein the sintering comprises a pressureless sintering process. 
     
     
         15 . The method of  claim 11 , wherein the iron-based alloy is approximately 2-25% of the overall weight percentage of the sintered tungsten carbide and iron-based alloy. 
     
     
         16 . The method of  claim 11 , wherein the tungsten carbide comprises approximately 90 wt % and the iron-based alloy comprises approximately 10 wt % of the overall weight percentage of the sintered tungsten carbide and iron-based alloy. 
     
     
         17 . The method of  claim 11 , wherein the tungsten carbide comprises a substantially same size before and after undergoing sintering. 
     
     
         18 . The method of  claim 11 , wherein the tungsten carbide comprises an average microparticle size of approximately 0.5-20 μm. 
     
     
         19 . (canceled) 
     
     
         20 . The method of  claim 11 , wherein the iron-based alloy binder comprises zirconium.