Tecnologo mecanico

File: Issue: Supercedes:

1.9.1.2-10T O10504 L10906

Praxair and TAFA Arc Spray Aluminum Bronze - 10T
Material Review:
Made exclusively for arc spraying. Characteristics of the coating are very high bond strengths and its ability to produce a dense, wear resistant surface, advantageous for machine element work. The use of 1/16 wire with this material has the added advantage of fumereduction during spraying. The prealloyed wire produces superior bond coats that are dense, resistant to corrosion, mechanical and thermal shock. The material is very suitable as a one-coat system and machines very easily to a finish of 5 micro inches. The unusual self-bonding ability of the alloy is attributed to the exceptionally high temperatures the alloy reaches, and which on impact with the basematerial, diffuses to form a metallurgical bond. One of the major problems in achieving high quality, well-bonded coatings in any thermal spray process is the expensive and extensive preparation of the substrate. Aluminum bronze eliminates the problem. The coating, through extensive testing, has been found to be far superior to that produced by most materials, not only in bond strength, but also insharp edge and impact loading. Aluminum bronze is self-bonding to a broad range of smooth metal surfaces including annealed or hardened carbon steels, hardened alloy steels, stainless steels, cast iron, and copper based alloys. It is highly recommended as the bond coat of choice for copper based alloys, as the nickel aluminum bond coats do not bond well to copper substrates. The fact that the highperformance characteristics are obtained only with the wire arc spray process is attributed to the higher temperatures achieved--arc temperatures in the range of 7000-12,000°F-which produce superheated particles. Arc Spray 10T aluminum bronze wire can be sprayed with any Praxair and TAFA Arc Spray gun. CAUTION: All Praxair and TAFA wires have been optimized for arc spraying. Use of alternate wiresusually cause problems such as excessive tip wear, spitting and feed problems. We only recommend Praxair and TAFA certified wires.

Application Review:
Recommended for all general metallizing work with bronze. This material is an extremely effective bond coat where surface preparation may be less than optimum; for example, on cast iron or steel. It is also used as a coating in its own rightand has the highest corrosion resistance and maximum wear resistance of the arc spray bronzes. Major uses, in addition to bond coats, are for bearings in the steel industry and for reclaiming aluminum/bronze components, including propeller shafts for operation in sea water. Praxair and TAFA 10T aluminum bronze can be machined but, again, grinding will give a better surface. Arc spray coats from0.004" (0.01 mm) to 0.006" (0.015 mm) can be readily applied in one pass. Thicker coatings up to 1/4 inch (6.3 mm) have been applied by continuous spraying. Thus, in some cases, 10T can be used as a one-coat system. Coatings can be machined to a medium finish with high speed tools or ground to smooth finish with aluminum oxide or silicon carbide wheels. It can be sprayed directly on a chemically cleansurface without conventional blasting, turning or roughening, thereby eliminating the need for expensive preparation equipment and the associated labor and quality control.

Composition
Copper Aluminum Iron Balance 7.0 percent 0.5 percent

Coating Physical Properties
Wire Size Deposit Efficiency Melting Point Bond Strength Coating Texture (as sprayed) Texture (as machined) Hardness CoatingDensity Coating Weight Shrink Impact, Sharp Edge & Bend Resistance 1/16" (1.6 mm) 80 Percent* 1800°F (982°C) 6066 psi (41.8 MPa) clean surface 6740 psi (46.5 Mpa) blasted surface Variable* 30-100 Microinches aa ** 55-60 Rb 144 (Knoop100) 6.3 gm/cc** 0.033 lbs/ft /mil. 0.0055 in/in (cm/cm) Excellent
2

Spraying
Spray Rate Coverage (wire consumption) Spray Pattern*** (approximate 8" standoff)...