32 research outputs found
Selective Growth of Low Stored Energy Grains During δ Sub-solvus Annealing in the Inconel 718 Nickel-Based Superalloy
The microstructure stability during δ sub-solvus annealing in Inconel 718 was investigated, focusing on the conditions that may lead to the development of very large grains (about 100 μm) in a recrystallized fine grained matrix (4 to 5 μm) despite the presence of second-phase particles. Microstructure evolution was analyzed by EBSD (grain size, intragranular misorientation) and SEM (δ phase particles). Results confirm that, in the absence of stored energy, the grain structure is controlled by the δ phase particles, as predicted by the Smith–Zener equation. If the initial microstructure is strained (ε < 0.1) before annealing, then low stored energy grains grow to a large extent, despite the Zener pinning forces exerted by the second-phase particles on the grain boundaries. Those selectively growing grains could be those of the initial microstructure that were the least deformed, or they could result from a nucleation process. The balance of three forces acting on boundary migration controls the growth process: if the sum of capillarity and stored energy driving forces exceeds the Zener pinning force, then selective grain growth occurs. Such phenomenon could be simulated, using a level set approach in a finite element context, by taking into account the three forces acting on boundary migration and by considering a realistic strain energy distribution (estimated from EBSD measurements). © 2015, The Minerals, Metals & Materials Society and ASM International
Influence of oxidation on fatigue crack initiation and propagation in turbine disc alloy N18
Lettera di Flageolet a Pier Andrea Saccardo
Rigny, 1905
Titolo attribuito dal catalogatore
Lettera manoscritta
datata: Rigny sur Arroux 1 aout 1905
La c. 2 v è bianca
Fondo Saccardo, 192
Lettera di J. Flageolet a Pier Andrea Saccardo
Rigny, 1909
Titolo attribuito dal catalogatore
Lettera manoscritta
datata: Rigny 10/2 09
Fondo Saccardo, 192
Lettera di J. Flageolet a Pier Andrea Saccardo
Rigny, 1913
Titolo attribuito dal catalogatore
Lettera manoscritta
datata: Rigny 11 oct. 1913
la c. 2v è bianca
Fondo Saccardo, 192
Lettera di J. Flageolet a Pier Andrea Saccardo
Rigny, 1912
Titolo attribuito dal catalogatore
Lettera manoscritta
Datata: Rigny 29 mars 1912 Saone et Loire
La c 2v è bianca.
Fondo Saccardo, 192
Lettera di J. Flageolet a Pier Andrea Saccardo
Rigny, 1916
Titolo attribuito dal catalogatore
Lettera manoscritta
datata: Rigny sur Arroux 1[5] mai 1916
Nota manoscritta a matita a c. 1v
Fondo Saccardo, 192
Lettera di J. Flageolet a Pier Andrea Saccardo
Rigny, 1912
Titolo attribuito dal catalogatore
lettera manoscritta
datata: Rigny 31 oct. 1912
Fondo Saccardo, 192
Lettera di J. Flageolet a Pier Andrea Saccardo
Rigny, 1915
Titolo attribuito dal catalogatore
Lettera manoscritta
datata: Rigny 16 mai 1915
Fondo Saccardo, 192
Lettera di J. Flageolet a Pier Andrea Saccardo
Rigny, 1912
Titolo attribuito dal catalogatore
Lettera manoscritta
datata: Rigny s. Arroux 15 Avril 1912
La c. 2v è bianca
Nota manoscritta a matita a c. 2r
Fondo Saccardo, 192