SPRAY FORMEDALLOY 625 TUBULARS A.L. MORAN, W.A. PALKO, C.J. MADDEN, P. KELLEY DAVID TAYLOR RESEARCH CENTER, ANNAPOLIS, MD 21402 Abstract Two series of Alloy 625 tubular preforms were spray deposited to evaluate the sensitivity of the alloy to spray deposition parameters. Variations in the metal flow rate, atomization pressure, substrate translation velocity, and melt size were made to determine their effect on the resulting preform microstructure, distribution and percent porosity, and tensile properties. All preforms were evaluated in the as-sprayed condition. Changing the gas to metal ratio (metal flow rate/atomizing gas pressure) did not result in significant variation in microstructure but did affect the amount of porosity in the preform. Porosity levels were generally greatest near the inner diameter of the preform and diminished through the remainder of the thickness. Preliminary tensile results from specimens located away from the inner diameter exhibited consistently high tensile strength. Bulk density measurements were calculated for the second series of preforms and demonstrated a dependence on processing parameters. Superalloys 718,625 andVariousDerivatives EditedbyEdwardA.I.aria TheMinerals,Metals& MaterialsSociety, 1991 843