Formation of MC-γ/γ′ eutectic fibers and their effect on stress rupture behavior in D/S Mar-M247LC superalloy

The influence of carbon addition on carbide characteristics and mechanical properties of CM-681LC superalloy using fine-grain process

“…The carbides play a very important role in superalloys and the amount, size and shape of carbides have the decisive effect on mechanical properties [4][5][6][7][8]. The present results demonstrate that the total area fraction of carbides and the linear density of MC and M 23 C 6 carbides at GBs increase greatly by carbon addition, which proves that the amount of carbides in 15C are more that those in 11C.…”

“…The present results demonstrate that the total area fraction of carbides and the linear density of MC and M 23 C 6 carbides at GBs increase greatly by carbon addition, which proves that the amount of carbides in 15C are more that those in 11C. The more carbides precipitated within the grain interior could improve the strengthening effect by preventing the movement of dislocations; the more carbides precipitated at GBs could increase the strength of GBs and improve the mechanical properties, since the carbides can postpone the crack extending and avoid the grain boundary sliding [6][7][8]10,15]. Thus, the tensile strength, yield strength and elongation of 15C could be improved effectively.…”

“…Because of the extremely brittle property of MC carbides, they may act as crack initiation sites and propagation paths. Therefore, adding the proper proportion of carbon with the carbide precipitation in the appropriate amount, size, and shape is likely to improve the mechanical properties of alloys [6][7][8][9][10].…”

Solution heat-treatment of Nb-modified MAR-M247 superalloy

“…According to literature, niobium is a refractory element that is normally present in the composition of nickel-based superalloys, found mainly in the γ′ phase (replacing aluminum) and in the formation of different types of carbides at the grainboundaries [11,12]. Considering solution heat-treatment, niobium increases γ′ solvus temperature, avoiding the dissolution of this phase at lower temperatures.…”

Oxidation behavior of a single-crystal Ni-base superalloy between 900 and 1000°C in air

“…Carbon is used to improve grain boundary properties while Al and Cr are added to develop oxidation resistance. These alloys possess not only improved mechanical properties, such as stress rupture [1,2] and fatigue resistance [3,4], but also better oxidation and hot corrosion resistance [5][6][7].…”