METHOD OF DIFFUSION WELDING OF BUTT JOINTS OF WORKPIECES FROM TITANIUM ALLOYS Russian patent published in 2024 - IPC B23K20/14 B23K20/22 B23K103/14 

FIELD: welding.

SUBSTANCE: invention relates to methods of diffusion welding using an intermediate screen of articles made from titanium and its alloys and can be used in various industries when producing thermomechanical devices, implanted structures used in medicine, etc. Method includes installation of welded workpieces in required position in screen relative to each other, heating of workpiece connection point to welding temperature and performance of welding itself. Protective screen is made on one of the welded workpieces as a whole with the workpiece itself in the form of a ring with cross-section in the form of an isosceles rectangular triangle with the size of the base L=(0.3-0.5) mm, which with its base faces the workpiece end face. During assembly, contact of the edge of the cylindrical end of the other workpiece with the surface formed by the hypotenuse of the above triangle is provided. Welded workpieces are installed with end gap s=(0.1-1) mm between their welded surfaces. Welding point is heated to temperature range of 800-925 °C, after which conditions are provided for development of process of auto-evacuation of obtained volume between ends of workpieces and wall of protective screen. Welded workpieces are held in the mode of auto-evacuation to dissolve the formed embrittlement layer at the ends of the workpieces being welded for a period of time defined by the expression: τ=4.88·s^0.75(7.7lgB+16.5)·10^-11exp(265000/RT), where: τ is the holding time before applying the compressive pressure, s; s is the value of the end gap, mm; B is the value of residual pressure in the welding chamber, Pa; R is universal gas constant; T is temperature. Compressive pressure Q is applied to the workpieces and the workpieces are welded along their welded end surfaces.

EFFECT: preservation of physical and mechanical properties and microstructure of joined alloys.

1 cl, 1 dwg