PSI - Issue 56

Sai Kumar Balla et al. / Procedia Structural Integrity 56 (2024) 41–48 Author name / Structural Integrity Procedia 00 (2019) 000 – 000

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Tungsten carbide coated with an 8 mm diameter tool helped in removing the outer surface from the AlSi12 specimen.

(a)

(b)

(c)

(d)

Fig. 2. Different post processing techniques adopted (a) sand blasting (b) chemical anodizing (c) wire-EDM and (d) micro milling

2.3. Surface roughness Surface roughness was measured for as-built and post-processed AlSi12 alloy samples using a non-contact optical profilometer (Olympus DSX1000) as shown in Fig. 3. The profilometer utilizes the principles of optical light interference to scan and the surface features of the samples are calculated. Instead of using a diamond-tipped probe, optical profilometry employs light to find surface abnormalities. Using this non-contact method, a three-dimensional surface measurement is obtained. However, just like a contact stylus profilometer, all optical profilometers can display two-dimensional surface outputs. Optical profilometer provided better results with high accuracy, measuring small features than contact profilometers. In contact profilometers, the stylus is getting contact with the surface, and there are chances for surface damage, which is eliminated with non-contact optical profilometers. Roughness is calculated for scanning area of 1 mm 2 on the surface for all the samples and measurements were taken at 3 different locations and average is noted.

Fig. 3. Olympus DSX1000 microscope used for surface roughness measurement

3. Results and discussion When assessing topography characteristics, surface roughness is a crucial component of surface integrity. The surface roughness (S a ) for different post processed conditions is evaluated and tabulated in Table 1 and the surface morphology is shown in Fig. 4.

Table 1. Surface average roughness (S a ) and their post-processing conditions

Condition

As-printed

Sand blasted

Chemical anodizing

Wire EDM

Micro milled