Prakt. Met. Sonderband 52 (2018) 349
MT
an was done in step sizes of 10 ym. After each time 50 um of Al alloy (5 steps of 10 yum) was
Mig milled away, a 2D OM image of the surface with the pivot arm at 45° was recorded (refer to
Ses By. figure 2). Allimages were taken with the M80 stereo microscope and 1C80 HD digital camera.
er oo The Al alloy sample was cleaned before imaging with alcohol and blown dry with
sg , on compressed air. The total thickness of the Al alloy material removed via milling was 2 mm,
vem corresponding to a total of 40 images in 2D. Image reconstruction in 3D from the stack of 40
cor rs alloy surface images was performed with the LAS X 3D Visualization software.
Figure 2: Images of the cross section (front face) of the Al alloy sample prepared with the
EM TXP system: A) initial surface before milling showing macroscopic defect (T-shaped
for polishing scratch); B) surface after first 50 um of material milled away (defect now more visible); C)
M80 stereo after second 50 ym milled away (total 100 um removed); and D) after third 50 um milled
yranaration of away (total 150 um removed).
ample can be
o the vertical
0 view of the 3. Results
ule or digital
MM at The total time to complete the entire workflow was just 1.5 hours. The workflow included:
¢ mounting of the Al alloy sample for preparation by milling and
« recording 40 images of the sample each time 50 ym of material was milled away.
When using more common methods for alloy sample preparation, normally the workflow
completion is much longer (4-10 hours).
= 30) welding Milling of the Al alloy sample produced high quality surfaces where the defect was clearly
visible. The 40 stereo microscope images of the sample in 2D allowed good quality 3D image
reconstruction with the LAS X 3D Visualization software. The 3D images of the defect have
The sample sufficient resolution for precise volume and surface area measurement (refer to figure 3).
ine Al alloy The defect volume was determined to be 429,000 um? (0.429 x 10-3 mm? equivalent to 0.429
