EXTENDED SOFTWARE POSSIBILITIES IN X-RAY MICROANALYSIS

HAL Id: jpa-00223964

https://hal.archives-ouvertes.fr/jpa-00223964

Submitted on 1 Jan 1984

HAL is a multi-disciplinary open access archive for the deposit and dissemination of sci- entific research documents, whether they are pub- lished or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers.

L’archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d’enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

EXTENDED SOFTWARE POSSIBILITIES IN X-RAY MICROANALYSIS

D. Grman, W. Muster

To cite this version:

D. Grman, W. Muster. EXTENDED SOFTWARE POSSIBILITIES IN X-RAY MICROANALYSIS.

Journal de Physique Colloques, 1984, 45 (C2), pp.C2-231-C2-234. �10.1051/jphyscol:1984251�. �jpa-

00223964�

JOURNAL DE PHYSIQUE

Colloque C2, suppl6ment au n02, Tome 45, f6vrier 1984 page mC2-231

EXTENDED SOFTWARE POSSIBILITIES I N X-RAY MICROANALYSIS

D. G r m a n and W.J. Muster

Swiss Federal Laboratories for Materials Testing and Research, CH-Diibendorf, SwitzerZand

RGsume - En microanalyse par rayons X, de nouvelles possibi- litgs intsressantes d'application de l'informatique ont et6 d6veloppges au cours de ces dernisres annges. Quelques-unes d'entre elles,

savoir notarnment les programmes QLA, TRACE,

et CALIB, sont decrites ci-aprGs. Elles r e l h e n t de l'uti- lisation, dans le domaine de la mgtallurgie, d'une microson- de glectronique "JEOL Superprobe JXCA-733" pilotge par ordina- teur .

Abstract - In recent years further interesting computer appli- cation in X-ray microanalysis have been developed. Some of the- se (QLA-, TRACE-, MAP- and CALIB-program) will be presented us- ing a computer controlled electron microprobe "JEOL Superprobe JXCA-733" for metallurgical applications.

QLA-program

This program makes it possible to check within a few minutes for the presence of totally 71 elements ranging from fluorine to uranium, and to print out the results in a hardcopy. In QLA-program, three channels [CH(I) to

] of spectrometers are scanned over their entire range and X-intensities of the mentioned elements are measured at the points corresponding to the caracteristics emission lines. An important ad- vantage of the energy dispersive method over wavelength dispersive systems has previously been the speed with which a general qualitative analysis could be obtained. This gap can now be closed for wavelength dispersive spectrometers by using the QLA-program, through which com- parable detection limits can be attained (see Table I). The substanti- ally higher energy resolution of the crystal spectrometer system also represents

great advantage, especially with a view to increasing analytical certainty. Rapid qualitative analyses with the aid of the QLA-program are to be recommended in the field of metallurgy above all for the investigation of slags (Fig. l), corrosion products, metal chips etc.

Table I - Detection limits in mass-% for selected steel elements by means of QLA-program for an accelerating voltage of 25 kV and a probe current of I O - ~ A . (The dectection limits may be improved by using higher probe currents.)

Element X-ray line mass-%

A1

0.08

S i

0.08

P K

a 0.3

S

a 0.3

T

i

a 0.4

V K

a 0.3

Element X-ray line mass-%

Cr

0.2

Mn K

0.2

CO

a 0.2

N

i

a 0.1

MO La 0.6

W L a 0.4

I

Article published online by EDP Sciences and available at http://dx.doi.org/10.1051/jphyscol:1984251

JOURNAL

DE

PfiOIct-CllRfFFK : ?+Q60F-08 < R ,

STOGF F O S . : X 13567 Y 2 2 7 0 4 7 1 1 4 0 7

X I 1 S i r n ' 0 F 1 8 . 3 2 0

UER 1.OG. AUSDRLICK U N T E R S C H E I D E T ZWISCHEN RESULTS:

THE FOLLOWING ELEMENTS ARE PRESENT MG, AL, 5 1 , K, CA, CR. MN, FE, N I

t H 7 2 ) PET

HG 5 . 6 5 0

N E b . 7 2 0 R U 5 . 8 4 1 X I f f 6 r b 7 ~3

P 6 . 1 6 0

UNTERGRUNIl UN18 ELEMENT ( t )

C H ( J ) L I F C O U N l I N T E N S I T Y ( L 0 G )

5 4 *********t 5 4 *********t 41 *******X*

4 0 *S*******

38 m********

3 6 ****L****

2 8 **%**%X*

2 6 Y Y I * * * * * 28 *X******

34 ******tt 16 ****X**

18 * * * * * W

2 8 4 3 *********tttttttttt 1 1

******

4 6 1 * * * * * * X * t t t t t t t 3 6 *****ttti

5 **tt 3

***

4 * * * t 4 ***t 4 ***t 3

***

1

*

1

*

Fig.

- QLA-analysis of slag in steel. Accelerating voltage 25 kV, probe current

O - ~ A .

For high-speed quantitative analysis recently a new semi-quantitative analysis program was developed which is aimed at performing qualita- tive analysis and obtaining the approximate results of quantitative analysis at high speed without requiring measurement of the specific standard specimen for the elements detected [

1.

TRACE-program

This computer controlled measuring process samples automatically with- in

certain wavelength range of the X-ray spectrum using a spectro- meter at high precision and with a minimum step of

micron. By this means even very low concentration (down to the ppm range) can be clearly established statistically. A typical, relevant practical exam- ple of this process is the detection of nitrogen when investigating stress corrosion cracking on brass. As Fig. 2 shows, the corrosion products on an opened fracture surface with small amounts of nitrogen (approx.

mass-%) reveal with the aid of the TRACE-program clearly the presence of the

K-emission band, whereas this element could not be detected at any of the points investigated when the process was not controlled by a computer.

Furthermore this program also represents a useful procedure for exam- ing the influence of chemical bonding on the X-ray emission spectra.

Fig. 3 shows a representation of the measured data for the investiga-

tion of the S Kp-emission bands emitted by FeS2 and FeS04. The clear

band separation makes it possible for corrosion investigations to de-

termine within a short time (approx. 5 min) the degree of oxidation of

the elements S or Fe contained in the corrosion products' and thus to

draw more precise conclusions concerning the corrosion mechanism. This

applies especially in the case of corrosion phenomena at locally li-

mited areas where other methods (X-ray fluorescence analysis, X-ray

diffraction, wet chemical methods) cannot be used.

Fig.

- Microanalytic evidence of bound nitrogen (nitrogen concentra- tion approx. 0.2 mass-%) in the corrosion products [ C U ( N H ~ )

on the opened fracture surface, determined by means of

K-emission band Analyser crystal STE, accelerating voltage 10 kV, probe current 3.10-g A, spectrometer step

(approx. 0.0658), meas. time/per step 10

5,030 5,035 5,040 X [l]

Fig. 3 - ^The

K@-emission band emitted by FeSos(a) and FeS2(b). Ana-

lyser crystal PET, accelerating voltage 15 kV, probe current 4.10'~~,

spectrometer step 10 gm (approx. 0.0003 A), meas. time/per step

C2-234 JOURNAL

DE

MAP-program

The program produces at various magnifications highly accurate two di- mensional X-ray contour maps, with the additional possibility of eva- luating ti~ese digital element maps semi-quantitatively over the entire concentration range. This allows interesting metallurgical investiga- tions, such as of segregation phenomena respectively diffusion zones.

CALIB-program

In special cases, the CALIB-computer-program enables the user to ob- tain more precise analytical results through the use of calibration curves than would be possible with the usual ZAF programs and the ap- plication of pure standards. One of its most important applications in the field of metallurgy is the analysis

the carbon content in steels, for example, when investigating case-hardened layers. The con- centrations which appear in this context (for the most part, between 0.1 and 1.0 mass-%) cause substantial difficulties with the usual ZAF corrections. By using the CALIB-program and special standard steel specimens, the carbon analysis is simplified considerably and its ac- curacy improved.

References

[ l ] ONO

JEOL

E , ^nO1