SPECIAL ALLOYS (CuAlNi)

History

Since the early 20th century, attempts have been made to cast aluminium bronze with methods commonly used for other copper alloys. Some researchers recognised the fundamental difficulties occurring with these alloys and developed corresponding manufacturing procedures to overcome them (Durville method).

The investigations by Carpenter and Edwards and by Rosenhain and Lautsburry laid the foundations for aluminium bronze.

Characteristics

AlBz alloys combined with the alloy elements Mn, Fe, Ni, Al play an outstanding role with regard to mechanical strength, creep resistance, alternating stress resistance and oxidation resistance even at high temperatures, wear and corrosion resistance. They also show excellent resistance to slightly acidic and weak alkaline salt solutions and to oxidating and reducing acids.

Applications / Products

AlBz alloys are meanwhile used in all areas of industry. This group of alloys is cast using sand casting, mould casting and continuous casting methods, and is also suitable for forging. Compared to other copper alloys, Cu-Al alloys have in some cases far higher strength values, thus allowing for reductions in weight in many cases thanks to reduced wall thickness. The good strength values also result in high wear resistance to abrasion, erosion and cavitation. Here the alloy group is even superior in some cases to stainless steel cast alloys. Practical applications include gliding and guide parts, impellers, pumps, turbines, ships' propellers, bearing bushes, parts exposed to seawater in marine technology and offshore technology.