A solder joint of 304L/Cu-Sn/Cu was brazed in furnace

and microstructure and mechanical properties of the brazed joint were analyzed and evaluated by OM

SEM

micro-hardness tester

tensile tester and fatigue tester.The results show that tightness of the joint exhibits desirable

and continuous strip structure can be observed at the junction of stainless steel and solder

which is composed of ferritic phase steel.The net-like intermetallic compound Cu31Sn8 attached ferritic stainless steel is grown to inside

and some bulk of intermetallic compound presents in the junction of ferritic stainless steel and Cu31Sn8

which may be Fe（Cr）P compound.Hardness of copper near the joint is decreased significantly

while the hardness change of 304 Lcan be ignored after brazed.Copper is cracked at place away from solder joint during tensile testing

where tensile strength of the joint reaches 240 MPa.After experienced about 50 million times cyclic load with 37 MPa stress amplitude

there is no crack in the specimen

which reveals that the brazed joint has excellent mechanical properties.