Alusil
Alusil as a hypereutectic aluminum alloy (AlSi17Cu4Mg) contains approximately 30% silicon and 70% aluminum [1], [2]. This alloy was created in 1927 by Schweizer & Fehrenbach [3] of Baden-Baden Germany and further developed by Kolbenschmidt [4]. The Alusil aluminum alloy is commonly used to make linerless aluminum engine blocks. Alusil, when etched, will expose a very hard silicon precipitate. The silicon surface is porous enough to hold oil and is an excellent bearing surface. BMW switched from Nikasil coated cylinder walls to Alusil in 1996 to eliminate the corrosion problems caused through the use of sulfur containing gasoline.
Engines using Alusil include:
- BMW M62 V8
- BMW N62 V8
- BMW N52 I6
- Porsche 928 V8
- Porsche 924S I4
- Porsche 944 I4
- Porsche 968 I4
- Porsche Cayenne V8