Hi all,
I'm not sure if this topic has been discussed elsewhere in the forum, but does anyone know if there has been any systematic study on the suitability of using NIST/NBS steel standards as microprobe standards, i.e. homogeneity of them at microscale? I understand the composition of most of the commercial available ones were based on bulk chemical analysis method. what is your experience with them?
Many thanks already.
Jeff
Hi Jeff,
I don't have a useful answer to your question other than I too am interested in finding the results of this.
Wondering whether we could expand the question to encompass other metal alloys, too: Al alloys specifically but also Ti, Mg etc
When I looked a while ago for standards, all the metallurgical standards I came across either said that weren't suitable for microanalysis or weren't homogeneous on a micron scale.
Jon
Quote from: jeffchen on April 18, 2018, 11:13:14 PM
Hi all,
I'm not sure if this topic has been discussed elsewhere in the forum, but does anyone know if there has been any systematic study on the suitability of using NIST/NBS steel standards as microprobe standards, i.e. homogeneity of them at microscale? I understand the composition of most of the commercial available ones were based on bulk chemical analysis method. what is your experience with them?
Many thanks already.
Jeff
Hi Jeff,
There is nothing systematic about the data below, but I threw a couple of NIST alloy SRMs that I had already mounted into the instrument over the weekend and run a bunch of elements on both. The data looks pretty good but I wasn't able to run a second set of standards for a drift correction as the filament blew during the last traverse.
I suspect the answer to your question is going to be "it depends". That is it depends on which SRM standards we are talking about. Here is the the first one I ran which is a NiFe alloy, SRM 1159 to be exact. First the major elements:
(https://smf.probesoftware.com/gallery/395_30_04_18_10_57_44.png)
Note that the Fe appears to vary a little, but according to the homogeneity range calculations below, the Fe is homogeneous within the 1% precision confidence interval. The minor and trace elements look like this:
(https://smf.probesoftware.com/gallery/395_30_04_18_10_58_01.png)
Clearly the Cu is *not* homogeneous, but the others look pretty good.
Finally I turned on the Homogeneity Range calculations from the Calculation Options dialog in the PFE Analyze! window and we get this output:
Range of Homogeneity (t-test) in +/- Elemental Weight Percent (Average of Sample):
ELEM: Ni Mo Cr Fe W Co Si Mn V Cu O
60ci .013 .000 .000 .017 --- .000 .001 .001 .000 .008 .000
80ci .021 .000 .000 .026 --- .000 .001 .001 .000 .012 .001
90ci .026 .000 .000 .034 --- .000 .001 .001 .000 .016 .001
95ci .032 .000 .000 .040 --- .000 .001 .001 .000 .019 .001
99ci .042 .000 .000 .053 --- .000 .002 .002 .000 .025 .001
Test of Homogeneity (t-test) at 1.0 % Precision (Average of Sample):
ELEM: Ni Mo Cr Fe W Co Si Mn V Cu O
60ci yes yes yes yes --- yes yes yes yes no yes
80ci yes yes yes yes --- yes yes yes yes no yes
90ci yes yes yes yes --- yes yes yes yes no yes
95ci yes yes yes yes --- yes yes yes yes no yes
99ci yes no yes yes --- yes yes yes yes no yes
Level of Homogeneity (t-test) in +/- Percent (Average of Sample):
ELEM: Ni Mo Cr Fe W Co Si Mn V Cu O
60ci .0 .4 .2 .0 --- .1 .2 .2 .1 1.3 .2
80ci .0 .6 .4 .1 --- .2 .2 .2 .1 2.0 .3
90ci .1 .8 .5 .1 --- .2 .3 .3 .2 2.6 .4
95ci .1 .9 .6 .1 --- .3 .4 .4 .2 3.1 .4
99ci .1 1.2 .8 .1 --- .4 .5 .5 .3 4.0 .6
Range of Ideal Homogeneity (t-test) in +/- Elemental Weight Percent (Average of Sample) (Meisenkothen and Donovan):
ELEM: Ni Mo Cr Fe W Co Si Mn V Cu O
60ci .095 .000 .002 .050 --- .000 .006 .006 .000 .004 .001
80ci .145 .001 .003 .077 --- .000 .009 .010 .000 .007 .002
90ci .187 .001 .004 .099 --- .001 .011 .012 .000 .009 .003
95ci .223 .001 .005 .118 --- .001 .013 .015 .000 .010 .003
99ci .294 .001 .006 .155 --- .001 .018 .020 .000 .014 .005
Range of Actual Homogeneity (t-test) in +/- Elemental Weight Percent (Average of Sample) (Meisenkothen and Donovan):
ELEM: Ni Mo Cr Fe W Co Si Mn V Cu O
60ci .160 .000 .002 .205 --- .000 .006 .007 .000 .097 .005
80ci .244 .001 .003 .313 --- .001 .010 .010 .000 .148 .008
90ci .313 .001 .004 .402 --- .001 .012 .013 .000 .190 .010
95ci .374 .001 .004 .480 --- .001 .015 .016 .000 .227 .012
99ci .494 .002 .006 .635 --- .001 .020 .021 .000 .300 .016
Next I will look at SRM C2402, which is a very different story!
Now for SRM C2402 which is a Hastelloy material. First the major elements:
(https://smf.probesoftware.com/gallery/395_30_04_18_11_16_42.png)
I think we can all agree that this would not be suitable as a microanalytical standard! Next, a similar story, for the trace elements:
(https://smf.probesoftware.com/gallery/395_30_04_18_11_17_00.png)
And again, the homogeneity range calculations from the Calculation Options dialog:
Range of Homogeneity (t-test) in +/- Elemental Weight Percent (Average of Sample):
ELEM: Ni Mo Cr Fe W Co Si Mn V Cu O
60ci .235 .273 .037 .035 .037 .003 .024 .014 .000 .002 .007
80ci .358 .416 .056 .054 .056 .005 .036 .021 .001 .003 .011
90ci .460 .534 .072 .069 .072 .006 .047 .028 .001 .003 .014
95ci .548 .637 .086 .082 .085 .007 .056 .033 .001 .004 .016
99ci .722 .839 .114 .108 .112 .010 .073 .043 .001 .005 .021
Test of Homogeneity (t-test) at 1.0 % Precision (Average of Sample):
ELEM: Ni Mo Cr Fe W Co Si Mn V Cu O
60ci yes no yes yes yes yes no no yes yes no
80ci yes no yes yes no yes no no yes yes no
90ci yes no yes yes no yes no no yes yes no
95ci no no yes no no yes no no yes yes no
99ci no no yes no no yes no no yes no no
Level of Homogeneity (t-test) in +/- Percent (Average of Sample):
ELEM: Ni Mo Cr Fe W Co Si Mn V Cu O
60ci .5 1.6 .2 .5 1.0 .2 2.7 2.0 .1 .4 3.8
80ci .7 2.4 .4 .7 1.5 .3 4.1 3.0 .2 .6 5.8
90ci .9 3.1 .5 1.0 1.9 .4 5.3 3.9 .3 .8 7.4
95ci 1.1 3.7 .5 1.1 2.2 .5 6.3 4.7 .3 .9 8.9
99ci 1.4 4.8 .7 1.5 3.0 .7 8.3 6.1 .4 1.2 11.7
Range of Ideal Homogeneity (t-test) in +/- Elemental Weight Percent (Average of Sample) (Meisenkothen and Donovan):
ELEM: Ni Mo Cr Fe W Co Si Mn V Cu O
60ci .095 .093 .061 .019 .030 .008 .009 .010 .001 .003 .001
80ci .145 .141 .092 .028 .046 .012 .013 .015 .002 .005 .002
90ci .186 .181 .119 .037 .059 .016 .017 .019 .002 .006 .003
95ci .222 .216 .141 .044 .071 .019 .021 .023 .003 .008 .003
99ci .292 .285 .186 .057 .093 .024 .027 .030 .004 .010 .004
Range of Actual Homogeneity (t-test) in +/- Elemental Weight Percent (Average of Sample) (Meisenkothen and Donovan):
ELEM: Ni Mo Cr Fe W Co Si Mn V Cu O
60ci 4.588 5.329 .722 .689 .714 .062 .465 .275 .007 .034 .135
80ci 6.990 8.119 1.099 1.050 1.087 .095 .708 .420 .011 .052 .205
90ci 8.978 10.429 1.412 1.348 1.397 .122 .909 .539 .014 .067 .264
95ci 10.705 12.434 1.684 1.608 1.665 .146 1.084 .643 .016 .080 .315
99ci 14.094 16.372 2.217 2.117 2.192 .192 1.427 .846 .022 .105 .414
Quote from: Probeman on April 30, 2018, 11:20:13 AM
Now for SRM C2402 which is a Hastelloy material. First the major elements:
(https://smf.probesoftware.com/gallery/395_30_04_18_11_16_42.png)
I think we can all agree that this would not be suitable as a microanalytical standard! Next, a similar story, for the trace elements:
(https://smf.probesoftware.com/gallery/395_30_04_18_11_17_00.png)
And again, the homogeneity range calculations from the Calculation Options dialog:
Range of Homogeneity (t-test) in +/- Elemental Weight Percent (Average of Sample):
ELEM: Ni Mo Cr Fe W Co Si Mn V Cu O
60ci .235 .273 .037 .035 .037 .003 .024 .014 .000 .002 .007
80ci .358 .416 .056 .054 .056 .005 .036 .021 .001 .003 .011
90ci .460 .534 .072 .069 .072 .006 .047 .028 .001 .003 .014
95ci .548 .637 .086 .082 .085 .007 .056 .033 .001 .004 .016
99ci .722 .839 .114 .108 .112 .010 .073 .043 .001 .005 .021
Test of Homogeneity (t-test) at 1.0 % Precision (Average of Sample):
ELEM: Ni Mo Cr Fe W Co Si Mn V Cu O
60ci yes no yes yes yes yes no no yes yes no
80ci yes no yes yes no yes no no yes yes no
90ci yes no yes yes no yes no no yes yes no
95ci no no yes no no yes no no yes yes no
99ci no no yes no no yes no no yes no no
Level of Homogeneity (t-test) in +/- Percent (Average of Sample):
ELEM: Ni Mo Cr Fe W Co Si Mn V Cu O
60ci .5 1.6 .2 .5 1.0 .2 2.7 2.0 .1 .4 3.8
80ci .7 2.4 .4 .7 1.5 .3 4.1 3.0 .2 .6 5.8
90ci .9 3.1 .5 1.0 1.9 .4 5.3 3.9 .3 .8 7.4
95ci 1.1 3.7 .5 1.1 2.2 .5 6.3 4.7 .3 .9 8.9
99ci 1.4 4.8 .7 1.5 3.0 .7 8.3 6.1 .4 1.2 11.7
Range of Ideal Homogeneity (t-test) in +/- Elemental Weight Percent (Average of Sample) (Meisenkothen and Donovan):
ELEM: Ni Mo Cr Fe W Co Si Mn V Cu O
60ci .095 .093 .061 .019 .030 .008 .009 .010 .001 .003 .001
80ci .145 .141 .092 .028 .046 .012 .013 .015 .002 .005 .002
90ci .186 .181 .119 .037 .059 .016 .017 .019 .002 .006 .003
95ci .222 .216 .141 .044 .071 .019 .021 .023 .003 .008 .003
99ci .292 .285 .186 .057 .093 .024 .027 .030 .004 .010 .004
Range of Actual Homogeneity (t-test) in +/- Elemental Weight Percent (Average of Sample) (Meisenkothen and Donovan):
ELEM: Ni Mo Cr Fe W Co Si Mn V Cu O
60ci 4.588 5.329 .722 .689 .714 .062 .465 .275 .007 .034 .135
80ci 6.990 8.119 1.099 1.050 1.087 .095 .708 .420 .011 .052 .205
90ci 8.978 10.429 1.412 1.348 1.397 .122 .909 .539 .014 .067 .264
95ci 10.705 12.434 1.684 1.608 1.665 .146 1.084 .643 .016 .080 .315
99ci 14.094 16.372 2.217 2.117 2.192 .192 1.427 .846 .022 .105 .414
Thanks for this John. I've got a bunch of NIST alloy standards, I suppose I'll check them through. Would be good if we could build some sorta database for them collectively.
Quote from: jeffchen on May 06, 2018, 10:39:52 PM
Thanks for this John. I've got a bunch of NIST alloy standards, I suppose I'll check them through. Would be good if we could build some sorta database for them collectively.
Julien Allaz, Owen Neill and Anette von der Handt have organized a standards "focus interest group" (FIG) that is having a meeting at the Baltimore MAS meeting this summer.
The first goal of the group is to document the standards that are already "out there". I will re-post Julien's email from the list server if you missed it.
john
Edit by John: Of course this site would be happy to host such a database as well. I assume it will primarily be a "homogeneity on the microscale" database since the average compositions of these materials are already well characterized.
I wonder if NIST has any internal studies of the microscale homogeneity of these materials...
Hello All,
The NIST data on homogeneity is located in their Special Publications list. The pdf's all begin with SP260-xxx there are a few that specifically address microanalysis. There was also a special edition of the Journal in 2002 that exclusively discussed microbeam standards. Google will get you there fastest.
FYI the pucks were good for XRF because the entire surface (the right face always marked) is assayed. So Charles Taylor didn't exactly read the manuals when he chopped them up...
I found the certificates of analysis to contain useful information and the archival certificates are on a separate webpage at nist.gov so you can download them for free.