- 2000 AUG 04 -


00-08-04    .....   The following email was received from Jim FOOT with details of upcoming tests.

From: Foot, Jim []     Sent: Thursday, August 03, 2000 10:43 AM

To: 'Bruno Stutz - SR Technics'; 'Pamela Rosnik - Boeing'; Gerden, Vic;   'Frank Hilldrup'

Cc: 'Ray Maiorana'; 'Mark Ryan - Hollingsead'; A98H0003; Vance, Larry;  Garstang, John; ''

Subject: Auger (AES) Update

             The following provides a brief overview of the future work TSB is planning with respect to the copper arced beads.

 1) Eighteen of the arced exhibits chosen from the previous AES study will be subjected to FIB ion milling (sample size ~ 20 um wide by 10 um deep) to further characterize the bead to determine homogeneity, morphology and porosity.  It is estimated that up to ten of this samples will be subjected to TEM analysis.  The FIB ion milling will be accomplished by FIBICís in Ottawa. A schedule has not yet been determined. However, it is suspected that the work will be accomplished overnight as an operator is not required to be present once the machine is set-up. Dr. Brown will select the sites to be milled.

 2) AES will be used to characterize the surface region of 6, 12 AWG triple twisted, tin plated copper wire strands (from the seawater trial test) plus similar new wires for reference. Strands of nickel-plated 6AWG with and without seawater exposure will also be examined.

 3) XPS (X-ray photoelectron spectroscopy) will be used to characterize three types of precipitates found on copper arc melt wires retrieved from seawater tests and, determine the elements present in various wire insulation's, Tefzel (orange/blue/white), double jacketed Tefzel (white/blue), and Kapton film.

 4) A new technique has been developed to non-destructively examine the interior of small samples and produce a high-resolution magnified image.  A combination of X-ray transmission technique along with tomographical reconstruction allows to get three-dimensional information about the internal microstructure.  In this case any internal area can be reconstructed as a set of flat cross sections, which can be used to analyze two and three-dimensional morphological parameters. The company which developed the method and performs this service is Sky Scan, located in Antwepsesteenweg 28, Aartselaar B2630, Belgium.  The TSB is looking at the feasibility of having all of the arc-melt samples examined by this method.  Once a decision has been made we will keep you informed.

          Please feel free to contact me if you have any questions.

Best regards,  Jim Foot,  613 990-0913 (Ottawa Office),  613 xxx-xxxx (Cell)

            In paragraph 1, it would seem that the FIB/TEM process will be going ahead shortly.  Eighteen exhibits is over half of the thirty-three beads.  Then ten will be TEM examined.  Nothing to indicate what exhibits, but again this appears to be up to Dr. BROWN.  It would seem that he is being given free reign to select and do as he sees fit.  While a schedule has not yet been developed, it seems apparent in the email that Jim FOOT does not expect anyone from outside to attend the process.  It had been mentioned previously that the process was an automated process and can be accomplished overnight.

            Paragraph 2 describes the intent to AES examine further triple twisted wires (the IFEN wires).  I suspect that this is in relation to the tests for aluminium migrations along the outside of the wire, and those wires have already been supplied.  This seems to be external migration, and its value is not certain at this time, as it is on the exterior of the wire.

            Paragraph 3 describes the XPS analysis.  Once again, he is examining the material on the exterior of the wire, and this is not seen as important at this time, as it relates to post-crash artefacts, and not pre-crash influence.  The fact that magnesium or whatever is on the outside is not important, it is what is on the inside that is.  It can be reasonably shown that nothing migrated to the wire interior.  The examination of the insulation is of value, as it will determine if there is magnesium present.  These tests have been performed, and no magnesium was found.

            Finally, paragraph 4 describes the Sky Scan process.  What is important is that they intend to examine all of the wire melts.  This is a positive move.  The potential problem only lies with the transportation of the exhibits. 

            I will prepare a short email to Jim FOOT regarding the potential problems of transportation, and suggest that Andy KERR be used to carry the exhibits.  It will take too long to wait for Insp. LATHEM to go through Vic GERDEN.  I have already recommended this route to John GARSTANG, and he said that he would approach Vic GERDEN on the matter. 



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