Thermal Spray Coated Engine Valve for Increased Wear Resistance

Abstract

A valve for use in an internal combustion engine is disclosed. The valve includes a stem connected to a fillet disposed between the stem and a seat face. A port receives the stem and accommodates a seat insert that engages the seat face when the valve is in a closed position. The seat insert is fabricated from a non-cobalt-based alloy or an iron-based alloy and the seat face is coated with a cobalt-based alloy or a nickel-based alloy. The coating may be applied using a thermal spray process, such as HVOF.

1 . A valve for use in an internal combustion engine, the valve comprising:
 a stem connected to a fillet, the fillet connecting the stem to a seat face;   a port that receives the stem and accommodates a seat insert that engages the seat face when the valve is in a closed position;   the seat insert being fabricated from a non-cobalt-based alloy; and   the seat face being coated with a cobalt-based alloy or a nickel-based alloy.   
     
     
         2 . The valve of  claim 1  wherein the cobalt-based alloy covers the seat face and not the fillet. 
     
     
         3 . The valve of  claim 1  wherein the seat face is disposed between the fillet and a margin, the cobalt-based alloy covering the seat face and not the fillet or the margin. 
     
     
         4 . The valve of  claim 1  wherein the cobalt-based alloy is coated onto the seat face using a thermal spray process. 
     
     
         5 . The valve of  claim 4  wherein the thermal spray process is high velocity oxygen fuel (HVOF) process. 
     
     
         6 . The valve of  claim 1  wherein the non-cobalt-based alloy is an iron-based alloy. 
     
     
         7 . The valve of  claim 1  wherein the non-cobalt-based alloy is J130. 
     
     
         8 . The valve of  claim 1  wherein the nickel-based alloy is a NiCrAlY alloy. 
     
     
         9 . The valve of  claim 1  wherein the cobalt-based alloy is STELLITE® 1. 
     
     
         10 . The valve of  claim 1  wherein the cobalt-based alloy is selected from the group consisting of STELLITE® 1, STELLITE® 3, STELLITE® 4, STELLITE® 6, STELLITE® 6B, STELLITE® 12, STELLITE® 21, STELLITE® 25, STELLITE® 31, STELLITE® 190, STELLITE® 694, STELLITE® 706, STELLITE® 712, STELLITE® F, STELLITE® Star 3, TRIBALOY® 400, TRIBALOY® 400C, TRIBALOY® 800, TRIBALOY® 900 and combinations thereof. 
     
     
         11 . The valve of  claim 1  wherein the cobalt-based alloy is STELLITE® 1 and the iron-based alloy is J130. 
     
     
         12 . The valve of  claim 1  wherein the cobalt-based alloy is coated onto the seat face with a thickness ranging from about 0.05 mm to about 2 mm. 
     
     
         13 . An internal combustion engine including the valve as defined in  claim 1 . 
     
     
         14 . An internal combustion engine, comprising:
 a cylinder block including at least one combustion chamber;   at least one air intake leading into the least one combustion chamber and defining a port configured to receive a valve;   the valve positioned within the at least one port for selectively opening and closing the port, the valve including a stem connected to a fillet that is connects the stem to a seat face, the seat face being coated with a cobalt-based alloy or a nickel-based alloy; and   the port accommodating a seat insert, the seat insert being fabricated from an iron-based alloy.   
     
     
         15 . The engine of  claim 14  wherein the nickel-based alloy is a NiCrAlY alloy. 
     
     
         16 . The engine of  claim 14  wherein the seat face is coated using a thermal spray process. 
     
     
         17 . The engine of  claim 14  wherein the cobalt-based alloy is selected from the group consisting of STELLITE® 1, STELLITE® 3, STELLITE® 4, STELLITE® 6, STELLITE® 6B, STELLITE® 12, STELLITE® 21, STELLITE® 25, STELLITE® 31, STELLITE® 190, STELLITE® 694, STELLITE® 706, STELLITE® 712, STELLITE® F, STELLITE® Star 3, TRIBALOY® 400, TRIBALOY® 400C, TRIBALOY® 800, TRIBALOY® 900 and combinations thereof. 
     
     
         18 . The engine of  claim 14  wherein the cobalt-based alloy is STELLITE® 1 and the non-cobalt based alloy is J130. 
     
     
         19 . The engine of  claim 14  wherein the cobalt-based alloy is coated onto the seat face with a thickness ranging from about 0.05 mm to about 2 mm. 
     
     
         20 . A method of improving the durability of an engine valve, comprising: providing a valve including a stem connected to a fillet that connects the stem to a seat face;
 providing an engine port for receiving the stem, wherein the port accommodates an iron-based seat insert that engages the seat face when the valve is in a closed position; and   thermal spray coating the seat face with a cobalt-based alloy or a NiCrAlY alloy.