A multi-stage hierarchical approach to alloy design
|Title||A multi-stage hierarchical approach to alloy design|
|Publication Type||Journal Article|
|Year of Publication||2010|
|Authors||Ray PK, Brammer T, Ye YY, Akinc M, Kramer MJ|
|Keywords||BORON, DEGREES-C, metals, MO5SI3, OXIDATION BEHAVIOR, temperature, total-energy calculations, wave basis-set|
A multi-stage hierarchical sieving approach based on a combination of semiempirical and ab initio calculations along with selected experimental studies was used to down-select potential alloy Systems for ultra-high-temperature applications. This approach indicates that the Mo-Ni-Al system has potential for applications at the target temperatures of 1,200-1,300A degrees C. The Mo was selected for its high melting temperature, room temperature toughness, and creep resistance while the NiAl is a reservoir for the Al (2) O (3) passivating scale. Microstructures based on casting and powder processing of the Mo-Ni-Al alloys were studied. Oxidation behavior of the Mo-Ni-Al alloys at 1,100 and 1,200A degrees C in dry air was determined and those alloys with a parts per thousand currency sign20 at. % Mo were shown to be superior to the T2 (Mo (5) SiB (2) ). Furthermore, the calculations predicted that small amounts of platinum group metals Pd, Ir, and Rh additions would increase the melting temperature without forming detrimental intermetallic phases, which results in improved oxidation stability of the NiAl phase.
|URL||<Go to ISI>://000283098900005|