Hexagonal close-packed (hcp) iron carbides play an important role in steel processing and in steel products. The recent discovery of novel ultrafine (2-5 nm) iron carbide (ε'-Fe2+xC) precipitates in TRIP steel sheds a new light on the hcp family of carbides. Here we present a first-principles study on the relative stability, and the electronic, magnetic properties of the ε'-Fe2C phases. Differe...

Thanks to their refractoriness, carbides are sensed as fuel coating for the IV generation of reactors. Among those studied, the Ti3SiC2 ternary compound can be distinguished for its noteworthy mechanical properties: the nanolamellar structure imparts to this material some softness as well as better toughness than other classical carbides such as SiC or TiC. However, under irradiation, its behav...

Within the framework of a systems approach, the design of a high performance stainless steel integrated processing/structure/property/performance relations with mechanistic computational models. Using multicomponent thermodynamic and diffusion software platforms, the models were integrated to design a carburizable, secondary-hardening, martensitic stainless steel for advanced gear and bearing a...

The conventional wisdom to tailor the properties of binary transition metal carbides by order-disorder phase transformation has been inapplicable for the machinable ternary carbides (MTCs) due to the absence of ordered phase in bulk sample. Here, the presence of an ordered phase with structural carbon vacancies in Nb4AlC3-x (x ≈ 0.3) ternary carbide is predicted by first-principles calculations...

First-principles electronic structure and positron state calculations for transition metal carbides and nitrides are performed. Perfect NaC1-structures as well as structures with metal or carbonJnitrogen vacancies are considered. The positron affinities and lifetimes are determined. The trends are discussed and the results are compared with recent positron lifetime measurements for group IV and...

Experimental details of atom probe field ion microscopy (APFIM) of a Ni-16Cr-9Fe alloy are presented. In particular, studies concerning analysis of intergranular carbides and borides and segregation to grain boundaries are described. It was found that NiZ3B6 precipitates are very sensitive to preferential field evaporation, which necessitates optimization of the analysis conditions. In the FIM ...

the purpose of this study was to investigate the effect of heat treatment including solution treatment and aging on the microstructure of cast nickel-based in100 superalloy including size, volume fraction and morphology of primary γ' and different kinds of carbides. for this purpose, different solution heat treatment cycles and a constant aging cycle were implemented on cast ingot samples and t...