Ampco 483 is a cast aluminum-nickel-iron-copper alloy (UNS 95800), commonly called alpha nickel aluminum bronze or propeller bronze.
Uses include: propeller blades and hubs, fittings, pump housings and impellers, gears, worm wheels, valve guides, seals, and structural applications requiring excellent corrosion resistance in both fresh and salt water.
Ampco 483 alloy will maintain mechanical properties at temperatures up to 600°F and has a machinability rating of 50%. The alloy was developed at the request of the U.S. Navy for critical salt-water service and provides excellent corrosion resistance to seawater and non-oxidizing acids. Can be welded with both the gas-shielded and shielded metal-arc processes. Brazing, soldering and oxyfuel gas welding are not recommended.
The microstructure of the as-cast alloy generally consists of continuous equiaxiated alpha crystals with small areas of metastable beta phase. Kappa phase precipitates are found in the alpha phase, in grain boundaries, and in the beta areas. A quench and temper thermal treatment results in refinement and redistribution of the kappa phase throughout a matrix of tempered beta martensite and alpha kappa eutectoid. Ampco 483 castings are always subjected to this thermal treatment to enhance corrosion resistance and eliminate the potential of any de-alloying.