Nial-base composite containing high volume fraction of AlN for advanced engines

A particulate reinforced NiAl-AlN composite comprising:

• a NiAl matrix having greater than about 13 volume percent particles of AlN therein and including a toughening alloy selected from the groups consisting of NiCrAlY, FeCrAlY and FeAl.

A method of preparing a particulate reinforced NiAl-AlN composite alloy comprising the steps of:

• cryomilling, in an attritor with an impeller having an arm, prealloyed NiAl in liquid nitrogen using grinding media having a diameter of about 3 mm, an impeller speed of from about 450 rpm to about 800 rpm for a duration from about 4 hours to about 20 hours to obtain a cryomilled powder which forms upon consolidation a particulate reinforced NiAl-AlN composite alloy comprising a NiAl matrix having greater than about 13 volume percent particles of AlN within said matrix;
• and
• consolidating the cryomilled powder to form said particulate NiAl-AlN composite alloy.

The method according to claim 16, wherein the cryomilling duration is about 16 hours.