Investigation of the Effect of Manufacturing Methods and Sr Addition on the Structure and Properties of Solder 34А (Al – 27% Cu – 6% Si)

The advantages and disadvantages of Russian solder 34А (Al–27% Cu–6% Si) used for brazing aluminium alloys are described. It is demonstrated that modification of solder by Sr significantly reduces the size and morphology of phases (Si and CuAl₂ ), but does not have a marked affected on mechanical and production properties. The structure and properties of solder bars prepared by vacuum suction casting, hot extrusion, and continuous casting are compared. The main regimes are determined for continuous casting and hot isothermal extrusion of solder metal rods 3-4 mm diameter. It is shown that the best mechanical properties are exhibited by rods prepared by hot extrusion with a degree of reduction of 300. It is shown that the manufacturing method of filler metal rods does not have a marked effect on spreading kinetics during brazing and on the sizes of structural components within brazed joints.