Standard Operation Procedure for measuring average ASTM grain size of non-equiaxed grain structure

Taken from http://www.tppinfo.com/

Methods

1. Lineal Intercept Procedure
2. Circular Intercept Procedures
   
   • Hilliard Single-Circle Procedure
   • Abrams Three-Circle Procedure
   
   

Procedure

Generally, for non-equiaxed structure, more information can be obtained by making separate size determinations along parallel line arrays that coincide with all the three principal directions of the specimen. Therefore, longitudinal (l), transverse (t) and plane (p) specimen sections are used. The number of intersection was counted. (An interception is a point where a test line is cut by a grain boundary.)

Lineal Intercept Procedure

1. The average grain size is estimated by counting the number if grains intercepted by one or more straight lines sufficiently long enough to yield at least 50 intercepts.
2. It is desirable to select a combination of test line length and magnification such that a single field will yield the required number of intercepts.
3. Usually the straight test lines will lie inside the grains, precision will be reduced if the average count per test line is low. If possible, use either a longer test lines or a lower magnification.
4. Use the test lines of known lengths and count the number of intersection on three to five blindly selected and widely separated fields and then an average number of intersections is calculated for all the principal directions planes l, t and p.
5. Mean number of interceptions per unit length, NL, on the fields of longitudinal (NL(l)), transverse (NL(t)) and planar (NL(p)) planes were thus calculated. (formula shown below)

Hilliard Single-circle Procedure

1. A single circle was used as test line. This will eliminate the problem of being bias when counting of the grain boundaries as in the Lineal Intercept method.
2. The test circle diameter should never be smaller than the largest observed grain.
3. Do not use a small test circle as it is rather inefficient as a great many fields must be evaluated to obtain a high degree of precision.
4. A small reference mark is placed at the top of the circle to indicate the place to start and stop the count.
5. Use the test lines of known circumferences (length) and count the number of intersection on three to five blindly selected and widely separated fields until sufficient counts are obtained to yield the required precision.
6. Repeat the previous step for all the principal directions planes l, t and p.
7. The mean number of interceptions per unit length, NL, on the fields of longitudinal (NL(l)), transverse (NL(t)) and planar (NL(p)) planes were thus calculated. (formula shown below)
8. Recommended 35 counts per circle with the test circle applied blindly over as large a specimen area as feasible until the desired total number of counts is obtained.

Abrams Three-Circle Procedure

1. From experiment finding that a total of 500 counts per specimen normally yields an acceptable precision.
2. Consists of three concentric and equally spaced circles having a total of 500mm
3. Use the circular test lines of known circumferences (length) and count the number of intersection on at least five blindly selected and widely separated field.
4. Separately record the count of the intersections per pattern for each of the tests.
5. Repeat the previous step for all the principal directions planes l, t and p.
6. Mean number of interceptions per unit length, NL, on the fields of longitudinal (NL(l)), transverse (NL(t)) and planar (NL(p)) planes were thus calculated. (formula shown below.

Calculation of results

• Use the following equation to find NL(n) for each principal direction plane

NL(n) =   Ni / (L/M)
  NL = mean number of interceptions per unit length,
Ni = the number of interceptions counted on the field,
L = the length of the test line(s) used,
n = the principal direction plane, and
M = the magnification.

• Take the equation below to find the average NL,:

NL = (NL(l) . NL(t) . NL(p) ) 1/3

• Calculate the mean lineal intercept Lm, for each field using the following equation:

Lm = 1/ NL

• Determine ASTM grain size number using the following equatio

G = (-6.6457 log10 Lm) – 3.298

References

1. ASTM E 112 – Standard test methods for determining average grain size, p229-251 (NTU)
2. Grain size measurement, p85-  (NUS TN689.2 Pra)
3. ASTM E 930-92 – Standard test methods for determining the largest grain observed in a metallographic section (ALA grain size), p666-670 (NTU)
4. ASTM E 1181-87 – Standard test methods for characterizing duplex grain sizes, p725-738 (NTU)
5. ASTM E 1382-97 – Standard test methods for determining average grain size using semiautomatic and automatic image analysis, p855-878 (NTU)
6. BS DD 44:1975 – Methods for the determination of grain size of non-ferrous alloys, p3-10 (NTU, BS)
7. JIS H 0501 – Methods for estimating average grain size of wrought copper and copper alloys, p261-165 (NTU)
8. Metal Handbook (Metallography) – Grain size & particle distribution, p129-134

How to measure grain size using ImageJ software

copy & paste from http://osdir.com/ml/java.imagej/2006-04/msg00010.html


---------------------------------------------------------------------------------------------------------------

Anneliese writes,

>
> Date: Sat, 1 Apr 2006 14:46:34 +0200
> From: Klughammer GmbH
> Subject: ImageJ and Metallography
>
> Dear users,
>
> has anybody already made some experience with ImageJ and metallography?
>
> I am looking for
>
> - grain size measurement
> - graphite morphology
> - nodularity measurement
> - particle size distribution
>
> Anneliese
>
And Noel replies.
Refer to the following books.
Computer aided Microscopy by John Russ,
Quantitative Stereology by E. E. Underwood,
and the paper by D.C. Sterio 1984 Journal of Microscopy. (the unbiased
estimation of number and sizes of arbitrary particles using the disector, J
microscopy. 134, 127.

Grain size measurement in metallography proves to be difficult because it is
usually next door to impossible to produce a perfect polish and etch which
reveals all boundaries with sufficient difference to the matrix.
Thus thresholding will be incomplete.
Once you have perfect boundaries, then life is easier.
By perfect boundaries I mean black boundaries on a pure white background.
You may measure grain sizes using all three methods easily.
Linear intercept,
Triple point counting,
And area measurement.

Here are some formulae which are commonly used. (From Russ. J.C. Computer
Assisted Microscopy, Plenum Press 1990, isbn 0-306-43410-5.
P 225.
ASTM grain size G
Using intercept method

G=(-6.6457Log[base10](1/PL))-3.298

Where PL is the number of points per unit length, measured in millimeters.

Or if you measure areas of the grain bodies,

(From Russ. J.C. Computer Assisted Microscopy, Plenum Press 1990, isbn
0-306-43410-5.
P 225.
G=(3.22 Log[base10](NA.M^2))-2.95

Where NA is number of grains per unit area on a polished surface at a
magnification M.

If you count the nodes where triple points are then G is got from
(From Russ. J.C. Computer Assisted Microscopy, Plenum Press 1990, isbn
0-306-43410-5.
P 147.

G=(log[base e]((Nodes/2)-1)/Area)/(log[base e](2)) -2.95.

Some investigators have found it quicker to produce a photo, and to trace
the boundaries out manually using a transparent film and a felt pen. The
resulting drawing is then scanned into the computer and processed in ImageJ.
This will be black and white and easily thresholded into a perfectly
segmented binary image. Such an image is the ideal to which your preparation
must aspire.

Otherwise it may be more time consuming.

If your specimens are suitable, and your etching superb, then
it may be possible to produce a perfect image via the image processing tools
in ImageJ.
Techniques to investigate include, thresholding, subtract background, find
edges, skeletonize, erode, dilate, open, close, watershed and so on.
Also useful may be techniques which differentiate between rough and
smooth, or surfaces with different textures.
Each type of material will have its own behaviour, and you must discover
this for yourself.

I have just talked about grains here.
The particle size distribution will be more straightforward, so long as the
particles are easily discriminated from the matrix. Just be careful that the
smallest particles you need to measure are "larger" than the resolution
limit.
The analyze particles menu in ImageJ will be what you use here.

And for Graphite morphology and nodularity, I have no experience.
But I am sure the methods to be used will have the parameters you need and
these will easily be employed in a macro.

Regards
Noel Goldsmith

Noel Goldsmith
Aircraft Forensic Engineering
Air Vehicles Division
DSTO
506 Lorimer Street
Port Melbourne
Vic 3207
AUSTRALIA
Phone (613) 96267538
FAX (613) 96267089
Email noel.goldsmith@xxxxxxxxxxxxxxxxxxx

1 day training session on our new stereomicroscope & metallurgical microscope

Salam & selamat sejahtera,

Dear colleague, brothers & sisters

Please plan to be at the 1 day training session on our new stereomicroscope & metallurgical microscope (basic unit) that will be held on

Date:   16^th September 2009 (Wednesday)

Time:   10.00 am

Place: Makmal Kubang Gajah (MBG2).

A very experience application specialist from Crest Systems (M) Sdn Bhd will be the speaker and he will share his knowledge on microscope instruments, application using stereomicroscope & metallurgical microscope in material/ metallurgical research and other fields, basic/ advance techniques image analysis and etc.

The topic of training basically covers

i)     Streomicroscope (OLYMPUS SZ61TR) – low power scope

ii)    Metallurgical microscope (BX51M) – high power scope

iii)   CMOS Digital Camera (Moticam 2300)

iv)   Basic Image Analysis (Image + 2.0 & Image Adv.)

§         Counting particle and measuring function (linear, area, angle, perimeter, etc)

§         Multilayer version  of the same image (each focused at a different position, can be combined produce a single focused image)

§         Image Calibration

Who knows, some of these systems and equipment may be able to solve problems at our lab session, or provide good tools for metallurgical/ materials teaching subject or furthering your R&D activities. Hope to see you there.

Thanks

Note: Postgraduate students or research asst. are also invited

STANDARD SETTING FOR IMAGE J SOFTWARE (Version 2 Plus)

ONLY VALID for Canon Camera Model PowerShot A470
7.1 MegaPixels
3.4x optical Zoom

Camera Setting
Resolution: 7M 3072X2304
Focus: Manual
Oxposure: 0
ISO: HI Auto
AWB: Auto

Microscope lens (X)	Eye piece (X)	camera zoom (X)	Total magnification (X)	Pixel	Known Distance (micron)
5	10	3.4	170	2356	1000
5	10	4	200	2788	100
5	10	5.1	255	2808	800
5	10	6.5	325	2736	600
5	10	8.2	410	2848	500
5	10	10	500	2820	400
5	10	14	700	2856	300
10	10	3.4	340	2872.2	600
10	10	4	400	2780	500
10	10	5.1	510	2856	400
10	10	6.5	650	2704	300
10	10	8.2	820	2856	250
10	10	10	1000	2844	200
10	10	14	1400	2940	160
20	10	3.4	680	2917	280
20	10	4	800	2856.8	230
20	10	5.1	1020	2824.6	180
20	10	6.5	1300	2992	150
20	10	8.2	1640	2752	110
20	10	10	2000	2820	90
20	10	14	2800	2912	70
50	10	3.4	1700	2876	120
50	10	4	2000	2752	10
50	10	5.1	2550	2776	80
50	10	6.5	3250	2760	60
50	10	8.2	4100	2268	40
50	10	10	5000	2156	30
50	10	14	7000	1892	20

STANDARD SETTING FOR IMAGE J SOFTWARE (Version 2)

ONLY VALID for Canon Camera Model PowerShot A470
7.1 MegaPixels
3.4x optical Zoom

Camera Setting
Resolution: 7M 3072X2304
Focus: Super Macro
Oxposure: 0
ISO: HI Auto
AWB: Auto

	Microscope lens (X)	Eye piece (X)	camera zoom (X)	Total Magnification (X)	Pixel	Known Distance (micron)
	5	10	1.0	50	697	1000
	5	10	1.2	60	829.34	1000
	5	10	1.5	75	1048	1000
	5	10	1.9	95	1342	1000
	5	10	2.4	120	1674	1000
	5	10	3.0	150	2094.1	1000
	5	10	4.0	200	2796	1000
	10	10	1.0	100	1378	1000
	10	10	1.2	120	1635	1000
	10	10	1.5	150	2073.1	1000
	10	10	1.9	190	2520	950
	10	10	2.4	240	2648	800
	10	10	3.0	300	2892	700
	10	10	4.0	400	2752	500
	20	10	1.0	200	2376	800
	20	10	1.2	240	2900.1	800
	20	10	1.5	300	2766.3	600
	20	10	1.9	380	2924.3	500
	20	10	2.4	480	2916	400
	20	10	3.0	600	2744.3	300
	20	10	4.0	800	2440.2	200
	40	10	1.0	400	2288.4	400
	40	10	1.2	480	2706.1	400
	40	10	1.5	600	2616	300
	40	10	1.9	760	2778	250
	40	10	2.4	960	2076	200
	40	10	3.0	1200	2586.1	150
	40	10	4.0	1600	2752	120
	50	10	1.0	500	2472.1	350
	50	10	1.2	600	2532.7	300
	50	10	1.5	750	2664.1	250
	50	10	1.9	950	2616.2	200
	50	10	2.4	1200	2524	150
	50	10	3.0	1500	2944.1	140
	50	10	4.0	2000	2796	100