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

A promising new aluminium alloy made by rapid solidification processin g (RSP) has high Si, Ni, and Mm contents. This RS alloy is promising f or use as dynamically loaded automotive parts at temperatures up to ab out 250-degrees-C. This is mostly attributed to the low coefficient of thermal expansion alpha; the high stiffness, fatigue strength, therma l stability and tensile properties are also important features. Experi mental data presented herein focus on the microstructure of the as-cas t and as-extruded RS material and on the physical and mechanical prope rties of extrusions and forgings. Compared with conventionally cast al uminium-silicon alloys, the RS alloy shows improved properties at both room and elevated temperatures. This is due to the refined microstruc ture (particles less than 5 mum), the high alloy contents and the nove l metastable phases. The properties and easy formability of the cost e ffective RS-Al alloys are promising with respect to commercialization and market competitiveness in the near future.