TY - JOUR
T1 - Simultaneous improvement in fracture toughness and oxidation resistance of Nb-Si based alloys by vanadium addition
AU - Guo, Yueling
AU - Jia, Lina
AU - Kong, Bin
AU - Zhang, Huarui
AU - Zhang, Hu
N1 - Publisher Copyright:
© 2017 Elsevier B.V.
PY - 2017/7/31
Y1 - 2017/7/31
N2 - The microstructural characterization, fracture toughness and oxidation resistance of Nb-15Si-24Ti-4Cr-2Al-2Hf (at%, V-free) alloys and Nb-15Si-24Ti-4Cr-2Al-2Hf-1V (at%, 1V) alloys were investigated. Results showed that the V-free alloys and 1V alloys both consisted of Nbss, αNb5Si3 and γNb5Si3 phases, and V was primarily partitioned in Nbss phases. Compared with the V-free alloys, the 1V alloys were featured by a better continuity of Nbss, finer average diameter of silicides and lower volume fraction of γNb5Si3. The 1 at% addition of V enhanced the fracture toughness of Nb-Si based alloys from 9.87 to 12.98 MPa m1/2 at room temperature. The fracture surfaces of 1V alloys were more undulated, compared with those of the V-free alloys. The 1 at% addition of V significantly improved the oxidation resistance of Nb-Si based alloys, by reducing the weight gain from 264.7 to 148.5 mg/cm2 after oxidation at 1300 °C for 100 h. The transition from a paralinear oxidation kinetic to a parabolic oxidation kinetic was triggered by the addition of V.
AB - The microstructural characterization, fracture toughness and oxidation resistance of Nb-15Si-24Ti-4Cr-2Al-2Hf (at%, V-free) alloys and Nb-15Si-24Ti-4Cr-2Al-2Hf-1V (at%, 1V) alloys were investigated. Results showed that the V-free alloys and 1V alloys both consisted of Nbss, αNb5Si3 and γNb5Si3 phases, and V was primarily partitioned in Nbss phases. Compared with the V-free alloys, the 1V alloys were featured by a better continuity of Nbss, finer average diameter of silicides and lower volume fraction of γNb5Si3. The 1 at% addition of V enhanced the fracture toughness of Nb-Si based alloys from 9.87 to 12.98 MPa m1/2 at room temperature. The fracture surfaces of 1V alloys were more undulated, compared with those of the V-free alloys. The 1 at% addition of V significantly improved the oxidation resistance of Nb-Si based alloys, by reducing the weight gain from 264.7 to 148.5 mg/cm2 after oxidation at 1300 °C for 100 h. The transition from a paralinear oxidation kinetic to a parabolic oxidation kinetic was triggered by the addition of V.
KW - Directional solidification
KW - Fracture toughness
KW - Heat treatment
KW - Nb-Si alloy
KW - Oxidation resistance
UR - https://www.scopus.com/pages/publications/85021271271
U2 - 10.1016/j.msea.2017.06.052
DO - 10.1016/j.msea.2017.06.052
M3 - Article
AN - SCOPUS:85021271271
SN - 0921-5093
VL - 701
SP - 149
EP - 157
JO - Materials Science and Engineering: A
JF - Materials Science and Engineering: A
ER -