The interfacial orientation relationship of oxide nanoparticles in a hafnium-containing oxide dispersion-strengthened austenitic stainless steel

Abstract

This work reports comprehensive investigations on the orientation relationship of the oxide nanoparticles in a hafnium-containing austenitic oxide dispersion-strengthened 316 stainless steel. The phases of the oxide nanoparticles were determined by a combination of scanning transmission electron microscopy-electron dispersive X-ray spectroscopy, atom probe tomography and synchrotron X-ray diffraction to be complex Y-Ti-Hf-O compounds with similar crystal structures, including bixbyite Y 2 O 3 , fluorite Y 2 O 3-HfO 2 solid solution and pyrochlore (or fluorite) Y 2 (Ti, Hf) 2−x O 7−2x. High resolution transmission electron microscopy was used to characterize the particle-matrix interfaces. Two different coherency relationships along with one axis-parallel relation between the oxide nanoparticles and the steel matrix were found. The size of the nanoparticles significantly influences the orientation relationship. The results provide insight into the relationship of these nanoparticles with the matrix, which has implications for interpreting material properties as well as responses to radiation.

Temperature dependent dispersoid stability in ion-irradiated ferritic-martensitic dual-phase oxide-dispersion-strengthened alloy: Coherent interfaces vs. incoherent interfaces

“…The size-coherency correlation has been observed in different types of ODS alloys [13,64e67]. In general, small dispersoids tend to be coherent with the matrix phase [13,64], and lose coherency as they become larger [13,64,65]. From a thermodynamics interpretation, this correlation is a result of the minimization of free energy [64].…”

On the microstructure and strengthening mechanism in oxide dispersion-strengthened 316 steel: A coordinated electron microscopy, atom probe tomography and in situ synchrotron tensile investigation

“…Therefore, oxide nanoparticles coupled with a finer grain structure are expected to give austenitic steels excellent radiation tolerance and mechanical strength with marginal compromise in the intrinsic advantages of austenitic steels. A series of ODS austenitic steels have been developed and proven to display the excellent conditions mentioned above [20][21][22][23][24][25].…”

Austenitic Oxide Dispersion Strengthened Steels : A Review

“…The MA parameters lie in the range of BPR 5:1 to 10:1, speed 300 RPM -600 RPM, and MA of these alloys is usually carried out up to 100 hours depending on the milling conditions. The reported consolidation parameters are 50 MPa to 100 MPa pressure with sintering temperature in range of 900 °C -1100 °C and holding time of about 5 min -15 min [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17] …”

“…There are different techniques used to characterise the clusters such as Z contrast mode, high angle annual dark field (HAADF), electron energy loss spectroscopy (EELS) and energy dispersive spectroscopy (EDS) 4,11 attachments in transmission electron microscope (TEM) [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17] , synchrotron x-Ray diffraction and atom probe tomography (APT) 4,11,15 . The APT, EELS, and EDS are used to analysis the chemical composition of the dispersoids.…”