TY - JOUR
T1 - High-temperature creep and oxidation behavior of Mo-Si-B alloys with high Ti contents
AU - Schliephake, Daniel
AU - Azim, Maria
AU - Von Klinski-Wetzel, Katharina
AU - Gorr, Bronislava
AU - Christ, Hans-Jürgen
AU - Bei, Hongbin
AU - George, Easo P.
AU - Heilmaier, Martin
PY - 2014/3/1
Y1 - 2014/3/1
N2 - Multiphase alloys in the Mo-Si-B system are potential high-temperature structural materials due to their good oxidation and creep resistance. Since they suffer from relatively high densities, the current study focuses on the influence of density-reducing Ti additions on creep and oxidation behavior at temperatures above 1273 K (1000 C). Two alloys with compositions of Mo-12.5Si-8.5B-27.5Ti and Mo-9Si-8B-29Ti (in at. pct) were synthesized by arc melting and then homogenized by annealing in vacuum for 150 hours at 1873 K (1600 C). Both alloys show similar creep behavior at stresses of 100 to 300 MPa and temperatures of 1473 K and 1573 K (1200 C and 1300 C), although they possess different intermetallic volume fractions. They exhibit superior creep resistance and lower density than a state-of-the-art Ni-base superalloy (single-crystalline CMSX-4) as well as other Mo-Si-B alloys. Solid solution strengthening due to Ti was confirmed by Vickers hardness measurements and is believed to be the reason for the significant increase in creep resistance compared to Mo-Si-B alloys without Ti, but with comparable microstructural length scales. The addition of Ti degrades oxidation resistance relative to a Mo-9Si-8B reference alloy due to the formation of a relatively porous duplex layer with titania matrix enabling easy inward diffusion of oxygen.
AB - Multiphase alloys in the Mo-Si-B system are potential high-temperature structural materials due to their good oxidation and creep resistance. Since they suffer from relatively high densities, the current study focuses on the influence of density-reducing Ti additions on creep and oxidation behavior at temperatures above 1273 K (1000 C). Two alloys with compositions of Mo-12.5Si-8.5B-27.5Ti and Mo-9Si-8B-29Ti (in at. pct) were synthesized by arc melting and then homogenized by annealing in vacuum for 150 hours at 1873 K (1600 C). Both alloys show similar creep behavior at stresses of 100 to 300 MPa and temperatures of 1473 K and 1573 K (1200 C and 1300 C), although they possess different intermetallic volume fractions. They exhibit superior creep resistance and lower density than a state-of-the-art Ni-base superalloy (single-crystalline CMSX-4) as well as other Mo-Si-B alloys. Solid solution strengthening due to Ti was confirmed by Vickers hardness measurements and is believed to be the reason for the significant increase in creep resistance compared to Mo-Si-B alloys without Ti, but with comparable microstructural length scales. The addition of Ti degrades oxidation resistance relative to a Mo-9Si-8B reference alloy due to the formation of a relatively porous duplex layer with titania matrix enabling easy inward diffusion of oxygen.
UR - http://www.scopus.com/inward/record.url?scp=84895922804&partnerID=8YFLogxK
U2 - 10.1007/s11661-013-1944-z
DO - 10.1007/s11661-013-1944-z
M3 - Article
AN - SCOPUS:84895922804
VL - 45A
SP - 1102
EP - 1111
JO - Metallurgical and Materials Transactions A: Physical Metallurgy and Materials Science
JF - Metallurgical and Materials Transactions A: Physical Metallurgy and Materials Science
SN - 1073-5623
IS - 3
ER -