There is then a further heating and cooling step in {HEAD ~ a reducing atmosphere} wherein the oxidised metallic component is reduced to {TAIL ~ a metal} 
There is then a further heating and cooling step in { HEAD ~ a reducing atmosphere } wherein the oxidised metallic component is reduced to { TAIL ~ a metal }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL