TY - JOUR
T1 - Effect of Ti (Macro-) alloying on the high-temperature oxidation behavior of ternary Mo-Si-B alloys at 820-1,300 C
AU - Azimovna Azim, Maria
AU - Burk, Steffen
AU - Gorr, Bronislava
AU - Christ, Hans-Jürgen
AU - Schliephake, Daniel
AU - Heilmaier, Martin
AU - Bornemann, Rainer
AU - Bolívar, Peter Haring
PY - 2013/10
Y1 - 2013/10
N2 - The aim of the present investigation was to gain an initial understanding of the effect of (macro-) alloying with Ti on the oxidation behavior of Mo-Si-B alloys in the ternary phase region of Mo-ss-Mo3Si-Mo 5SiB2 at 820-1,300 C. Motivated by recent studies and thermodynamic calculations, the alloy compositions Mo-9Si-8B-29Ti (at.%) and Mo-12.5Si-8.5B-27.5Ti (at.%) were selected and synthesized by arc-melting. Compared to the reference alloy Mo-9Si-8B, superior initial oxidation rates at 1,100-1,300 C as well as a significant density reduction by nearly 18 % were observed. Due to enhanced initial evaporation of MoO3 and mainly inward diffusion of oxygen, a borosilicate-rutile duplex scale with a continuous TiO2 phase had formed. Detailed investigations of the oxidation mechanism by SEM, EDX, XRD and confocal micro-Raman spectroscopy indicated that Ti alloying is promising with regard to further improvement of the oxidation resistance as well as the strength-to-weight ratio of Mo-Si-B alloys.
AB - The aim of the present investigation was to gain an initial understanding of the effect of (macro-) alloying with Ti on the oxidation behavior of Mo-Si-B alloys in the ternary phase region of Mo-ss-Mo3Si-Mo 5SiB2 at 820-1,300 C. Motivated by recent studies and thermodynamic calculations, the alloy compositions Mo-9Si-8B-29Ti (at.%) and Mo-12.5Si-8.5B-27.5Ti (at.%) were selected and synthesized by arc-melting. Compared to the reference alloy Mo-9Si-8B, superior initial oxidation rates at 1,100-1,300 C as well as a significant density reduction by nearly 18 % were observed. Due to enhanced initial evaporation of MoO3 and mainly inward diffusion of oxygen, a borosilicate-rutile duplex scale with a continuous TiO2 phase had formed. Detailed investigations of the oxidation mechanism by SEM, EDX, XRD and confocal micro-Raman spectroscopy indicated that Ti alloying is promising with regard to further improvement of the oxidation resistance as well as the strength-to-weight ratio of Mo-Si-B alloys.
KW - Mo-Si-B alloys
KW - Silica
KW - Titania
KW - Ultra-high temperature materials
UR - http://www.scopus.com/inward/record.url?scp=84885179355&partnerID=8YFLogxK
U2 - 10.1007/s11085-013-9375-1
DO - 10.1007/s11085-013-9375-1
M3 - Article
AN - SCOPUS:84885179355
SN - 0030-770X
VL - 80
SP - 231
EP - 242
JO - Oxidation of Metals
JF - Oxidation of Metals
IS - 3-4
ER -