ARMY TM 5-6115-612-34 NAVY AG-320B0-MME-000 (4) Spray coating (a) Place   part   In   fixture   designed   to   permit uniform coverage of areas designated to be coated (b) Preheat  the  cleaned  and  masked  parts  to 175-200° F (79-93° C) (c) Apply nickel alloy bond coat (item 140, appx B) onto designated areas to a thickness of 0 004-0 006 In (0 10-0 15 mm) 1 As   soon   as   spraying   operations   are started,  Introduce  a  stream  of  air  onto  the  part  being coated  to  maintain  a  part  temperature  not  higher  than 2500 F (1210 C) 2 Maintain cooling air blast throughout all coating operations (d) Apply low-alloy steel coating (item 13, appx B)   onto   the   designated   areas   to   a   total   thickness sufficient   to   meet   drawing   requirements   after   finish machining (e) The   spray   coating   must   Impinge   on   the surface to be coated at an angle of 75 to 105 degrees (1 31 to 1 83 radians) (f) Remove   masking   In   a   manner   that   will avoid damage to the sprayed coating e Quality (1) The  sprayed  coating  shall  be  adherent  to  the basis material and shall have a uniform surface    free from blisters,  chips,  or  other  objectionable  Imperfections  not readily removable by finishing operations (2) Coating   shall   be   free   from   grit   particles   and contamination  at  the  Interlace  between  the  coating  and substrate f Rejections  Parts  on  which  the  sprayed  coating does     not     conform     to     the     requirements     of     this specifications,   or   to   authorized   modification   shall   be subject to rejection g    Approved  Equipment  Any  model  Metco  type  E gun D-3   Plasma Spray Coating-Nickel Aluminum Composite. a Scope (1) Type This specification covers the procedure   for   plasma   spray   deposition   of   a   nickel- aluminum composite coating (Item 140, appx B) (2) Application  Primarily   to   provide   a   nickel- aluminum  composite  coating  as  an  undercoat  for  other spray coatings and  as  a  salvage  coating  for  build-up  of undersize parts b Applicable    Documents    The    latest    issue    of Aerospace Material Specifications (AMS) shall apply (1) Engineering Process Specifications • Vapor degreasing (Item 4, appx B) • Grit blasting (Item 3, appx B) • Acid cleaning (Item 2, appx B) (2) Engineering Material Specifications • Nickel-aluminum    composite    powder (Item 8, appx B) • Solvent, petroleum (item 5, appx B) c.   Requirements (1) Equipment  An  approved  metalizing  gun  to provide automatic gas pressure and powder feed control (2) Coating Materials Nickel-aluminum composite powder (item 8, appx B) d Procedure (1) Cleaning WARNING Toxic solvent is used for general cleaning Illness or skin    damage    may    be    caused    by    prolonged breathing    of    solvent    fumes    or    excessive    skin contact  with  the  liquid  Ensure  there  is  adequate ventilation  and  avoid  open  flame  or  sparks  when using flammable solvent (a) Titanium   Base   Parts   Parts   shall   be cleaned by washing In petroleum solvent (item 4,  appx B) or by wiping with a clean, lint-free rag (Item 7 appx B) dampened with keytone (Item 9, appx B) 14-2   Change 4