1) Precious metal alloy 
CuSil is a brand name for an alloy of 72% silver and 28% copper, that was once thought to have better properties than silver alone. According to Mr. Toshi Oyama, Ph.D. R&D Manager, WESGO Metals, `the thermal conductivity of CuSil was calculated from electrical conductivity, which is reasonable since both are controlled by free electrons in metals....