PSI - Issue 14

Anigani Sudarshan Reddy et al. / Procedia Structural Integrity 14 (2019) 449–466 Author name / Structural Integrity Procedia 00 (2018) 000–000

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3.4. Tensile properties of Hybrid specimens Figure 15 represents the comparison of mechanical properties (0.2% YS, UTS and % Elongation) between small scale and regular specimens. It can be seen there is no significant difference in properties in the as printed condition. Figure 16 represents the small scale and regular tensile specimen of the hybrid (SS316L on X20Cr13) after failure in as printed condition. In both cases, the failure lies in the DMLS SS316L, having a lower strength as compared to the martensitic X20Cr13. The interface or the DMLS hybrid joint region being intact in both small scale as well as the regular specimens. Figure 17 represents the comparison of properties of small scale in the as printed and heat treated condition. It can be seen that the tensile properties of the hybrid have decreased from 465 MPa to 397 MPa for 0.2% YS and 544 MPa to 517 MPa for UTS, whereas the % elongation remains same as 33% after heat treatment. However, there is no significant difference between the small scale and regular specimens, after heat treatment.

0 200 400 600 800

0 10 20 30 40 50

% Elongation

Hybrid_Small scale

Hybrid_Regular

Strength (MPa)

0.2% YS UTS % Elongation

Fig. 15. Comparison of mechanical properties of Small scale and Regular hybrid specimens (DMLS SS316L on X20Cr13 substrate) in the as printed condition

Interfac

X20Cr13

DMLS

Interfac

Fig. 16. Photograph showing the tensile specimens of small scale and regular after failure

600

0 10 20 30 40 50

400

200

% Elongation

0

Strength (MPa)

As printed Heat treated

0.2% YS UTS % Elongation

Fig. 17. Comparison of mechanical properties of hybrid (DMLS SS316L on X20Cr13 substrate) in the as printed and heat treated condition