PSI - Issue 71

R. Anil Kumar et al. / Procedia Structural Integrity 71 (2025) 302–308

306

of sample aged for 30 mins (107 HV) is just 6% lower than 114 HV. Considering this, a total of 4 samples (AB, 41, 44 and SR) were subjected to uniaxial tensile testing.

Fig. 4. (a) Variation of micro-Vickers hardness with post processing and (b) tensile behaviour of AlSi10Mg in selected conditions.

Table 2. Uniaxial tensile test results of AlSi10Mg in selected condition.

Sample Condition

0.2% Offset YS (MPa)

UTS (MPa)

Elongation (%)

As-built

272

408

4.8

245 °C - 30 mins

160

373

7.6

245 °C - 2 hrs

207

285

5.1

T5 300 °C - 2hrs

148

207

11.6

From Fig. 4b and Table 2, it is evident that as-built samples showcased higher UTS of 408 MPa in-line with literature but with a total elongation of 4.8%. Sample subjected to T5 treatment possessed improved ductility at the expense of strength which is reduced by almost 50% than that of as-built sample. This behaviour is widely attributed to breaking down of silicon network. Directly aged sample for 30 mins showed better combination of strength and ductility compared to that of the sample aged for 2hrs. The tensile behaviour is kind of contradicting the hardness behaviour though they are not directly related. This behaviour could be explained based on the experimental observations of Wu et al., which emphasizes the strengthening related to impeding the motion of dislocations (Wu et al., 2016). They experimentally observed that dislocations interact with nano-sized particles which are precipitated during rapid solidification using in situ TEM compression tests. This phenomenon is responsible for strengthening in as-built samples as well. During direct aging for 30 minutes, the cellular structure was preserved, and nano-sized silicon precipitates formed within the cellular structure. These precipitates originated from the supersaturated solid solution of α -aluminium, aligning with the findings reported in the literature (Park et al., 2021). The nanoprecipitates contribute to strengthening through precipitation hardening mechanisms. Additionally, it has been reported that the