Oxidation Resistance, Creep Strength and Room-Temperature Fracture Toughness of Mo–28Ti–14Si–6C–6B Alloy

From Mo–Si–B to Mo–Ti–Si–B Alloys: A Short Review

“…Comparison has been made for the creep behavior at 1200 • C between this alloy and other common high-temperature materials. Figure 12 [34] summarized the minimum creep rate of different alloy systems as a function of density-normalized applied stress, indicating the excellent creep resistance of this Mo-28Ti-14Si-6B-6C alloy. range of 1100 °C-1300 °C.…”

“…Comparison has been made for the creep behavior at 1200 °C between this alloy and other common high-temperature materials. Figure 12 [34] summarized the minimum creep rate of different alloy systems as a function of density-normalized applied stress, indicating the excellent creep resistance of this Mo-28Ti-14Si-6B-6C alloy. Note that the testing temperature (1200 °C) approaches the solvus temperature of the γ' phase in a single-crystal Ni-based superalloy CMSX-4; the creep strength of CMSX-4 is markedly inferior to those of the Mo-Si-B-or Mo-Ti-Si-B-based alloys [60].…”

“…In this view, besides the strengthening effect of TiC, the as-cast structure of a continuous BCC matrix highly contributes to the ductility of these alloys. The TiC-added Mo-Si-B alloys exhibit superior mechanical properties, including high room-temperature toughness and good high-temperature creep resistance [31][32][33][34][35]. However, in order to suppress the formation of extra (boro)silicides and reserve enough BCC phase to ensure its adequate toughness, high Si content, which is responsible for excellent oxidation resistance, is not permitted in these alloys.…”

“…Hereafter, Azim et al [58] further studied the creep behavior of several Mo-Ti-Si-B alloys with different phase constitutions in the temperature range of 1100 • C-1300 • C. Unlike the T 2 phase, which hardly crept at the testing temperature, the intermetallic phases of A15 and D8 8 could be deformed during creep, in which many dislocations were observed after the tests. Most recently, Hatakeyama et al [34] tested the Mo-28Ti-14Si-6B-6C (at.%) alloy at 1200 • C-1300 • C and 100 MPa-300 MPa. Based on the experimental data, they yielded the apparent activation energy of this alloy at 300 MPa to be 639 kJ/mol.…”

“…Unlike the T2 phase, which hardly crept at the testing temperature, the intermetallic phases of A15 and D88 could be deformed during creep, in which many dislocations were observed after the tests. Most recently, Hatakeyama et al [34] tested the Mo-28Ti-14Si-6B-6C (at.%) alloy at 1200 °C-1300°C and 100 MPa-300 MPa.…”