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Micro analysis of inclusions in copper wire

Background

Wire failures due to inclusions in the body of the wires are examined using the ZSX Primus Mapping/Micro Analysis feature. The CCD camera within the XRF unit allows for images to be taken thereby letting the user determine where the analysis should take place on the sample via a point and click function.

Investigation

A number of wires with imbedded inclusions which caused faults in the production of one long string of wire were submitted for analysis. The wires were placed in a sample cup and each was positioned to offer the best 'view' of the problem area for analysis. Semi-quantitative analysis was performed on each wire to determine the inclusion or fault composition located at the tip of the wires (Figures 1-3). No sample preparation was done other than an alcohol wipe and positioning the samples on a blank supporting substructure (a plastic pressing cap in this case) to prevent back scatter from the analysis chamber.

copper1
Figure 1: Wire 1
Copper2
Figure 2: Wire 1, alternate view
Copper3
Figure 3: Wire 2

Two spot analysis were taken on each sample - one on the shaft and one on the wire tip. See Figures 1-3. Semi-quantitative analysis was then performed using the Rigaku SQX analysis routine.

Some comparison scan examples are shown in Figures 4-8, the results are shown in Figures 4-5

Copper4
Figure 4: Wire 1 Ni
Copper5
Figure 5: Wire 1 Cr
Copper6
Figure 6: Wire Al
Copper7
Figure 7: Wire 2 Cr (tip-red, shaft-blue)
Copper8
Figure 8: Wire 2 Ni (tip-red, shaft-blue)

These results show a definite difference in the material being analyzed. From these results it can be determined where in the manufacturing process the inclusions originated.

Copper9
Wire
Copper10
Shaft
 
 
 534316 - Schaft  
 Massen % 
 534316 - Spitze  
 Massen %
C
ND
4.41
Cl
0.13
ND
Cr
ND
0.52
Fe
0.06
0.11
Ni
0.08
1.22
Cu
99.73
93.74

Table 2: Wire 2