Grain structure analysis

Toru HARA1), 1) National Institute for Materials Science, Sengen, Tsukuba, Ibaraki 305-0047, Japan

This work was supported by Cross-ministerial Strategic Innovation Promotion Program - Unit D66 - Innovative measurement and analysis for structural materials (SIP-IMASM).

Three-dimensional Structural Study of Microstructures in Advanced Materials.

Orthogonally-arranged FIB-SEM• Suitable for serial-sectioning• Various detectors can be applied• Ideal SEM observation condition

References(1) T.Hara, K.Tsuchiya, K.Tsuzaki, X.Man, T.Asahata,

A.Uemoto, J. Alloys and Compounds, 577, 717(2013).(2) T.Hara, KENBIKYO, 49, 53(2014). in Japanese.(3) SIP, Structural Materials for Innovation, C45 Oxide

Ceramics Matrix Composite Coating, (MHI Aero Engine, NIMS, Artkagaku, Nitivy), in Development of Ceramic Environmental Barrier Coating region.

� Every researchers can access the orthogonally-arranged FIB-SEM via Nanotechnology Platform program, MEXT.http://www.nims.go.jp/nmcp/

Summary

Samples

3D observation using ‘Orthogonally-arranged FIB-SEM‘

An example of applications

• Ceramic fibers (f~10mm) developed for CMC layer in ceramics coating.

• Main components are Silica and Almina.

• They are developed by SIP C45 ‘Oxide ceramics matrix composite coating’ group [3].

Introduction

The method of “Multiscale and multidimensional observation“ at the same sample area is established with applying orthogonally FIB-SEM and other microscopes.

3D analysis: Void structure

Crystal orientation analysis by EBSD and transmission-EBSD

STEM-EDS elemental analysis

��� �����������������������������������

0 +3+0 1+ + 0 ++3+0

Si-K Al-KSTEM-DF

10nmIQ Map IQ+IPF Map

We have developed the methodology for multiscalestructure analysis of materials based on a FIB-SEMtechnique[1][2]. With this method, higher contrast andresolution of 3D image is realized compare to conventionalmethods. We have applied this method on a ceramic fibersamples which have been developing in SIP program[3]

Various information on microstructure was obtained;(1)Void structure, relationship between void and grain,orientation dispersion of grains, were observed.(2) 3D microstructure, orientation, elemental distribution,high-resolution TEM can be obtained from one specimen.

In order to understand the microstructure of materialsaccurately, three dimensional (3D) analysis is essentiallyimportant, because the most of microstructures areconstructed in 3D. From this reason, we are developing amethodology of 3D microstructure analysis by using anorthogonally-arranged focused ion beam (FIB) – scanningelectron microscope (SEM) instrument. This equipment isspecially designed to observe the microstructure in 3Daccurately by a serial-sectioning method with very highcontrast and resolution.

Serial-sectioning

z: slice pitch

x,y: SEM(Mag., pixels)

Spatial resolution

z: ability of the FIB

x,y: SEM(Mag.)

Observation volume

A TEM sample can be picked up from the adjacent region of 3D obs.

20um

SEM

FIB

SEM

FIB

Two ways of serial-sectioningobs. at the edge

pick-up a cube

TEM sample

3D obs

δ-Ferrite

Tempered Martensite

2μm

An example of 3D reconstruction. Precipitates distribution in a heat-resistant steel.

Green: M23C6, Gray: MX MX distribution in a red box of the left figure.Orthogonal configuration is more suitable for precise 3D serial-sectioning

Sectioned plane is always perpendicular to SEM optic axis.