{HEAD ~ A subsequent heat treatment} may achieve {TAIL ~ the effect} of equalizing the concentration of aluminium between the repair layer and the region near the surface, and so the aluminium content required for new components is achieved again 
achieve
{ HEAD ~ A subsequent heat treatment } may achieve { TAIL ~ the effect } of equalizing the concentration of aluminium between the repair layer and the region near the surface , and so the aluminium content required for new components is achieved again
HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH