Conventional high temperature Aluminum alloys like A4032 or A2618 are in use for high performance pistons or Aerospace airframe components. There is a high demand for high temperature Aluminum alloys for these application because the low weight of Aluminum is from advantage for weight critical components. High strength a high temperatures is from significant advantage for the performance of the component. New high temperature Aluminum alloys could enter application that are now made of Titanium or even Steel.
Conventional high temperature Aluminum alloys show a significant drop in strength above 300°C. The effect of soaking reduces the strength after service times of several hundred of hours. This needs to be considered during designing and results often in higher component weight.
Like high strength Aluminum alloys most of the new high temperature alloys require new processing routes. Additionally processes like squeeze casting are in use for the production of particle reinforced Metal-Matrix-Composites.
The aim of these new processes is to obtain a finer microstructure and higher strength. The rapidly solidifying processes allow a higher solubility of alloying elements because of the higher cooling rate.
Aluminum Al-MS89 is a high temperature Aluminum alloy made via an advanced powder process. The alloy shows extrem temperature stability. Even after thousands of hours at high temperature the properties remains pretty stable. In contrast to many Aluminum-Silicon based alloys Al-MS89 shows also good ductility. Al-MS89 is available up to D=100mm. It can be used for advanced Automotive, Aeropsace, Semiconductor and other industrial application.
Aluminum Al-SF25 is an Aluminum-Silicon-Alloy made via spray forming. It shows a good combination of properties like high temperature strength, high stiffness and low CTE. Al-SF25 shows excellent machining behaviour compared to other Aluminum-Silicon-Alloys. Like most of the Aluminum-Silicon-Alloys, Al-SF25 show a comparable low ductility. This needs to be considered during part designing.
Aluminum Al-MD20 is made via spray forming. Al-MD20 is a Aluminum-Silicon-Alloy with very high Magnesium content. Because of the high Magnesium content it has a low density. The low density, high temperature strength and comparable high modulus makes it from interest for many technical applications.
DSC-Aluminum is a Metal-Matrix-Composite. A ceramic preform made of nanoscale (200-400 nm) Alumina particles is infiltrated either with pure Aluminum or an Aluminum alloy. Because of the nanoscale particle size dispersion-strengthening occurs. This results in a significant increase of strength. Dispersion-strengthened Materials like DSC-Aluminum show excellent temperature strength and stability. The ceramic particles increase the elastic modulus and so the stiffness significantly. The thermal coefficient of expansion (CTE) is lower than for conventional Aluminum alloys. DSC-Al is a material of choice for components requiring high temperature strength and/or stiffness.