A precipitation strengthened nickel based welding material that comprises 5-15 wt. % Co, 5-25 wt. % Cr, 1-6 wt. % Al, 0.05-0.2 wt. % C, 0.015-0.4 wt. % B, 1-3 wt. % Si, chemical elements selected from among tungsten and molybdenum from about 1 to 20 wt. %, chemical elements selected from among titanium, zirconium, hafnium, tantalum and rhenium from about 1 to 18 wt. % and nickel with impurities to balance, wherein the boron content is inversely proportional to silicon content and decreases from about 0.3 wt. % to about 0.015 wt. % when silicon content increases from about 1 wt. % to about 3 wt. % produces sound high strength and high oxidation resistance crack free welds on precipitation strengthened superalloys and single crystal materials.