The metallic substrate and or {HEAD ~ layer} may be made from an alloy such as a Cobalt or {TAIL ~ a Nickel based superalloy} 
The metallic substrate and or { HEAD ~ layer } may be made from an alloy such as a Cobalt or { TAIL ~ a Nickel based superalloy }
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL