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Engineering Science in
Additive Manufacturing HIP temperature effects on LPBF Hastelloy X

coarsening of carbides along the grain boundaries, which failure mode at room temperature was characteristic of
eventually envelop the grains and increase the brittleness ductile fracture.
of the grain boundaries, as shown in Figure 5. During
subsequent plastic deformation, the secondary cracks were 3.3. Mechanical properties at high temperature
induced through crystal fractures. Furthermore, higher To evaluate high-temperature mechanical properties, the
39
magnification images revealed numerous dimples in the tensile results of HIP specimens at 900°C are presented in
fracture surface of all specimens, proving that the tensile Figure 9. As reported in recent studies, 19-21,40 HIP treatment
significantly improved the high-temperature mechanical
properties compared to the as-built condition. The yield
strength, tensile strength, and elongation obtained in the
high-temperature tensile test were lower than those at
room temperature. As HIP temperature increased, the
yield strength exhibited no significant changes, while the
elongation gradually increased, reaching a maximum
value of 29.0% at HIP1210. Interestingly, the trend for
tensile strength at high temperature differed from that
observed at room temperature. The tensile strength of the
specimen at HIP1210 reached 236 MPa, representing an
improvement of 9.8% and 6.3% compared to the HIP1100
and HIP1180 specimens, respectively.
The carbide morphology within the high-temperature
deformation region and the statistical diagrams of
Figure 9. The yield strength, tensile strength, and elongation obtained at
high temperatures for HIP1100, HIP1180, and HIP1210 specimens carbide size distribution of HIP1100, HIP1180, and
Abbreviation: HIP: Hot isostatic pressing. HIP1210 specimens are displayed in Figure 10. After the

(A ) (A ) (A ) (A )
2
3
1
4

(B )
4
(B ) (B ) (B )
1
3
2

(C )
4
(C ) (C ) (C )
1 2 3

Figure 10. The carbide morphology of the deformation region failed at high tensile temperature, and the corresponding diagrams of carbide size
distribution. Results of (A -A ) HIP1100, (B -B ) HIP1180, and (C -C ) HIP1210 specimens. Scale bars: (A -C ) 20 μm; (A -C ) 10 μm; (A -C ) 1 μm,
3
3
1
2
2
1
1
4
4
1
1
4
magnifications: (A -C ) ×2,000; (A -C ) ×5,000; (A -C ) ×30,000.
1
1
3
3
2
2
Abbreviation: HIP: Hot isostatic pressing.
Volume 1 Issue 2 (2025) 9 doi: 10.36922/ESAM025240015