TY - JOUR
T1 - Mechanical properties of Mo-Nb-Si-B quaternary alloy fabricated by powder metallurgical method
AU - Byun, Jong Min
AU - Bang, Su Ryong
AU - Kim, Se Hoon
AU - Choi, Won June
AU - Kim, Young Do
N1 - Publisher Copyright:
© 2016 Elsevier Ltd
PY - 2017/6/1
Y1 - 2017/6/1
N2 - Mo-Si-B alloys composed of two intermetallic compound phases (Mo5SiB2 and Mo3Si) and a molybdenum solid solution matrix phase have been investigated for use as high-temperature structural materials due to their high melting point and good creep resistance. However, despite these advantages, Mo-Si-B alloys are difficult to use in practical applications because they have insufficient fracture toughness at room temperature. So, in many researches, microstructure control and the addition of other elements in the α-Mo matrix phase are conducted as an effective way to improve the fracture toughness. In this study, niobium (Nb) was added to a Mo-Si-B alloy by a powder metallurgical method to improve the mechanical properties. First, the Mo and Nb powders were pulverized by high-energy ball milling. Then, the synthesized intermetallic compound powders, which were fabricated by continuous heat treatment under a H2 atmosphere, were mixed with ball-milled Mo and Nb powder. Pressureless sintering was conducted at 1400 °C for 3 h under a H2 atmosphere. The Vickers hardness and fracture toughness were measured to investigate the mechanical properties of the sintered Mo-Si-B and Mo-Nb-Si-B alloy. The Vickers hardness was about 425 Hv for a Mo-Nb-Si-B alloy, which was lower value of 165 Hv compared to Mo-Si-B alloy (590 Hv). On the other hand, the fracture toughness of the Mo-Nb-Si-B alloy (14.5 MPa·√m) greatly increased compared to that of the Mo-Si-B alloy (12.6 MPa·√m).
AB - Mo-Si-B alloys composed of two intermetallic compound phases (Mo5SiB2 and Mo3Si) and a molybdenum solid solution matrix phase have been investigated for use as high-temperature structural materials due to their high melting point and good creep resistance. However, despite these advantages, Mo-Si-B alloys are difficult to use in practical applications because they have insufficient fracture toughness at room temperature. So, in many researches, microstructure control and the addition of other elements in the α-Mo matrix phase are conducted as an effective way to improve the fracture toughness. In this study, niobium (Nb) was added to a Mo-Si-B alloy by a powder metallurgical method to improve the mechanical properties. First, the Mo and Nb powders were pulverized by high-energy ball milling. Then, the synthesized intermetallic compound powders, which were fabricated by continuous heat treatment under a H2 atmosphere, were mixed with ball-milled Mo and Nb powder. Pressureless sintering was conducted at 1400 °C for 3 h under a H2 atmosphere. The Vickers hardness and fracture toughness were measured to investigate the mechanical properties of the sintered Mo-Si-B and Mo-Nb-Si-B alloy. The Vickers hardness was about 425 Hv for a Mo-Nb-Si-B alloy, which was lower value of 165 Hv compared to Mo-Si-B alloy (590 Hv). On the other hand, the fracture toughness of the Mo-Nb-Si-B alloy (14.5 MPa·√m) greatly increased compared to that of the Mo-Si-B alloy (12.6 MPa·√m).
KW - Fracture toughness
KW - Mo-Si-B alloy
KW - Niobium
KW - Pressureless sintering
KW - Vickers hardness
UR - http://www.scopus.com/inward/record.url?scp=85008600355&partnerID=8YFLogxK
U2 - 10.1016/j.ijrmhm.2016.10.008
DO - 10.1016/j.ijrmhm.2016.10.008
M3 - Article
AN - SCOPUS:85008600355
SN - 0263-4368
VL - 65
SP - 14
EP - 18
JO - International Journal of Refractory Metals and Hard Materials
JF - International Journal of Refractory Metals and Hard Materials
ER -