MECHANICAL-PROPERTIES OF A RAPIDLY SOLIDIFIED AL-SI-NI-MN ALLOY

A promising new aluminium alloy made by rapid solidification processing (RSP) has high Si, Ni, and Mm contents. This RS alloy is promising for use as dynamically loaded automotive parts at temperatures up to about 250-degrees-C. This is mostly attributed to the low coefficient of thermal expansion alpha; the high stiffness, fatigue strength, thermal stability and tensile properties are also important features. Experimental data presented herein focus on the microstructure of the as-cast and as-extruded RS material and on the physical and mechanical properties of extrusions and forgings. Compared with conventionally cast aluminium-silicon alloys, the RS alloy shows improved properties at both room and elevated temperatures. This is due to the refined microstructure (particles less than 5 mum), the high alloy contents and the novel metastable phases. The properties and easy formability of the cost effective RS-Al alloys are promising with respect to commercialization and market competitiveness in the near future.