Abstract: A process is provided for crack-free welding a nickel based single crystal superalloy article containing at least 5 weight % total of Al and Ti. The process comprises: melting an article surface to be welded and a filler alloy with an energy source, preferably a laser, wherein the filler alloy is a composition of a nickel based single crystal superalloy except that the total of Al and Ti is reduced below 5 wt %; allowing the melted article surface and filler alloy to solidify to form a bead of deposit; providing a plurality of beads of adjacent deposits covering the article surface to be welded; and remelting the adjacent beads of deposits with the energy source to provide vertically oriented crystal growth in the deposits.