Observation of Precipitation Evolution in Fe-Ni-Mn-Ti-Al Maraging Steel by Atom Probe Tomography

Abstract

We describe the full decomposition sequence in an Fe-Ni-Mn-Ti-Al maraging steel during isothermal annealing at 550°C. Following significant pre-precipitation clustering reactions within the supersaturated martensitic solid solution, (Ni,Fe) 3 Ti and (Ni,Fe) 3 (Al,Mn) precipitates eventually form after isothermal aging for~60 seconds. The morphology of the (Ni,Fe) 3 Ti particles changes gradually during aging from predominantly plate-like to rod-like, and, importantly, Mn and Al were observed to segregate to these precipitate/matrix interfaces. The (Ni,Fe) 3 (Al,Mn) precipitates occurred at two main locations: uniformly within the matrix and at the periphery of the (Ni,Fe) 3 Ti particles. We relate this latter mode of precipitation to the Mn-Al segregation.

Microstructural evolution of Mn-based maraging steels and their influences on mechanical properties

“…The characterisation of the precipitate and its effect on maraging behaviour have been investigated [15] [20][21] [22][23] [24]. However, this type of Fe-Mn-(Ni) alloy suffers from severe embrittlement.…”

Precipitation hardening of biodegradable Fe–Mn–Pd alloys

“…The accommodation of strain can be facilitated by Mn enrichment of the Pd-rich zones. Here, we should note that for cluster sizes smaller than 1 nm (corresponding to only about 40 atoms), solute concentration analysis may give an overestimate due to the difficulty of ascribing a detected ion to either the matrix or the cluster [36]. It is not clear whether the reduction in cluster Pd content during aging actually occurs, or if it is just a result of uncertainties in the evaluation algorithm.…”

Microstructure and Mechanical Properties of Al–Co–Cr–Fe–Ni Base High Entropy Alloys Obtained Using Powder Metallurgy

“…6b, an increased concentration of Ni and Al was registered, suggesting the existence of a B2 ordered NiAl phase. It is well known that aluminum together with Ni could form precipitations of ordered NiAl [43][44][45] or Ni 3 Al [40,46].…”

“…It is well known that nickel enhances the austenite phase field in steel [20,42], while aluminum promotes the formation of a BCC structure [20,24]. Furthermore, together they can form NiAl type precipitations of an ordered structure [43][44][45][46].…”