Bismuth is used as a replacement for lead, if you want lower temperature solder. 58Bi/42Sn alloy is cheap and about as good as Pb/Sn, but is more susceptible to

Bismuth is used as a replacement for lead, if you want lower temperature solder. 58Bi/42Sn alloy is cheap and about as good as Pb/Sn, but is more susceptible to thermal fatigue. I used 57Bi/42Sn/1Ag to solder heatpipes. Works great!