Electrically Conductive Epoxy
With a volume resistivity of .005, silver coated nickel (product #40-3909) from Epoxies Etc. provides a reliable electrical connection at about half the price of silver-filled epoxies. Because of its ability to cure at room temperature and easy 1:1 mix ratio, this material works well for repairs, even in the field. Cure time can be accelerated with heat as well.
40-3909 is also thermally conductive and has great bonding strength. It has been used in the assembly and repair of printed circuit boards, connectors, waveguides, high frequency shields, and as a cold solder. 40-3909 works well on surfaces that traditional solders cannot adhere to such as aluminum and plastics.
Source: Epoxies, Etc.