A method of forming a weld interface between a first workpiece and a second workpiece includes arranging a reactive braze material at a first joining surface of the first workpiece. The reactive material is selected to react upon being heated to a temperature below the solidus temperature of the first and second workpieces to form a liquid-containing reaction product. Furthermore, an assembly is prepared of the first workpiece and the second workpiece with the first joining surface of the first workpiece and a second joining surface of the second workpiece separated by the reactive material. The second workpiece is then heated with a first laser beam following a first path and with a second laser beam following a second path.