Stability calculation of Cu_4Ti intermetallic compound with addition of 3d transition metal in Cu-Ti alloy by density functional theory

摘要

Cu is widely used as an electronic circuit component because of its high conductivity. However, in order to be used as connector materials, high strength as well as the high conductivity is required to maintain the desired shape. The Cu-Ti alloy is one of precipitation hardening alloys, having two types of the precipitates: meta-stable beta'-Cu_4Ti and thermodynamically stable beta-Cu_4Ti.[1] In general, the precipitation hardening alloys can be strengthened more by additional cold working after aging. However, these precipitates dissolve in Cu matrix during cold working, lowering the conductivity considerably.[2] To obtain high conductivity and high strength simultaneously, it is essential to solve this problem.