The outer metal layer is formed of a first metal that has {TAIL ~ a coefficient} of thermal expansion larger than a coefficient of {HEAD ~ thermal expansion} of a second metal that forms the inner metal layer 
The outer metal layer is formed of a first metal that has { TAIL ~ a coefficient } of thermal expansion larger than a coefficient of { HEAD ~ thermal expansion } of a second metal that forms the inner metal layer
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH