Abstract
The influence of solution heat treatment on microstructure and tensile property of Inconel 718 formed by high-deposition-rate laser metal deposition has been investigated in this paper. Two different heat treatment regimes were employed: 1100 °C × 0.5 h/WQ+720 °C × 8 h/FC to 620 °C × 8 h/AC (this type of samples is called type-S) and 1100 °C × 1 h/WQ+720 °C × 8 h/FC to 620 °C × 8 h/AC (this type of samples is called type-L). The results showed that niobium segregation and Laves phases were eliminated both in type-S and type-L samples. This means that heat treatment at 1100 °C for no more than 0.5 h is enough, if initial epitaxial columnar grains are needed and niobium segregation and Laves phases are tend to be removed. Twins only existed in type-L sample, which was the main reason why the elongation of type-L was superior to that of type-S. The fracture mechanism of these two samples was microvoids coalescence ductile rupture. The separation of the granular sub-micron particles and the γ matrix was the main nucleus of the micro-voids.
| Original language | English |
|---|---|
| Pages (from-to) | 389-399 |
| Number of pages | 11 |
| Journal | Journal of Alloys and Compounds |
| Volume | 740 |
| DOIs | |
| State | Published - 5 Apr 2018 |
Keywords
- High-deposition-rate laser metal deposition
- Inconel 718
- Solution heat treatment