Alloy nickel diffusion strong and method for repairing welding superalloys.

A powder composition brazing alloy comprising: (a) at least one alloy powder low melting point, and (b) at least one alloy powder high melting point, wherein said at least one alloy powder comprises high melting point 50-70% Ni, 2-10% Cr, 2-10% Ta, 5-15% Co, 2-10% Al, 2-10% W, 2-4% Re yy up to 3% each of Mo and Hf, characterized in that said at least one alloying powder with low melting point comprises 50-70% Ni, 8-20% Cr, 8-15% Ta, 4-10% Co , 2-7% Al, and up to 2, 25% B.