Then {TAIL ~ at least one metallic layer} is sprayed on {HEAD ~ the laser shock peened surface area} of the substrate 
Then { TAIL ~ at least one metallic layer } is sprayed on { HEAD ~ the laser shock peened surface area } of the substrate
OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH