PSI - Issue 42

Bhandari et al. / Structural Integrity Procedia 00 (2019) 000–000

5

Litton Bhandari et al. / Procedia Structural Integrity 42 (2022) 529–536

533

a/a ' b

(1 0 1)

(0 0 2)

α/α '

α/α '

(1 1 0)

As-built

β

Intensity (a.u.)

HT

37

38

39

40

41

42

2 q (Degrees)

As-built

Intensity (a.u)

HT

30

40

50

60

70

80

90

2 q (Degrees)

Fig. 4. XRD Analysis of as-built and heat treated SLM Ti6Al4V alloy

Fig. 5. Surface morphology of SLM Ti6Al4V alloy

is deteriorated as compared to its conventional counterparts due to presence of process induced defects. These defects act as a stress raiser and crack initiates from them as confirmed by the fractographic analysis. The fracture surface was classified into three regions, namely (a) crack initiation zone, (b) crack propagation zone and (c) fast fracture zone, and are shown in Figure 7 . The crack initiation period consumes major fraction of the fatigue life. The initiation of the crack took place from the process-induced defects that are mainly located at the surface and subsurface regions. The crack initiation mechanism has been evaluated and various types of defects such as lack of fusion, porosity, unmelted powder particles were observed as shown in Figure 7. The process-induced defects were also present in the internal regions but crack initiated favourably from the surface and sub-surface region because of higher stress