Mo-Si-B alloys for ultrahigh-temperature structural applications.
A continuing quest in science is the development of materials capable of operating structurally at ever-increasing temperatures. Indeed, the development of gas-turbine engines for aircraft/aerospace, which has had a seminal impact on our ability to travel, has been controlled by the availability of materials capable of withstanding the higher-temperature hostile environments encountered in these engines. Nickel-base superalloys, particularly as single crystals, represent a crowning achievement here as they can operate in the combustors at ~1100 °C, with hot spots of ~1200 °C. As this represents ~90% of their melting temperature, if higher-temperature engines are ever to be a reality, alternative materials must be utilized. One such class of materials is Mo-Si-B alloys; they have higher density but could operate several hundred degrees hotter. Here we describe the processing and structure versus mechanical properties of Mo-Si-B alloys and further document ways to optimize their nano/microstructures to achieve an appropriate balance of properties to realistically compete with Ni-alloys for elevated-temperature structural applications.
Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.
J A
JA
Lemberg
R O
RO
Ritchie
D000497:Alloys / Q000737:chemistry*; D001895:Boron / Q000737:chemistry*; D055595:Mechanical Phenomena; D008982:Molybdenum / Q000737:chemistry*; D012825:Silicon / Q000737:chemistry*; D013696:Temperature
D000497:Alloys; D008982:Molybdenum; D001895:Boron; D012825:Silicon