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