Ni-base superalloy composition and method for SLM processing such Ni-base superalloy composition
A Ni-base superalloy composition to be used for powder-based additive manufacturing (AM) technology, such as selective laser melting (SLM) or electron beam melting (EBM). The cracking susceptibility during an AM process is considerably reduced by controlling the amount of elements, especially Hf, that form low-melting eutectics.
1. A nickel-base superalloy composition comprising a γ/γ′-microstructure with a chemical composition of (in wt. %):
9.5 W,
9.2 Co,
8.1 Cr,
5.6 Al,
3.2 Ta,
2.4 Hf,
0.7 Ti,
0.5 Mo,
0.075 C,
0.015 Zr,
0.015 B, and
balance Ni,
wherein cracking susceptibility is reduced by controlling an amount of elements that form low-melting eutectics, and wherein the elements that form low-melting eutectics include at least one of Hf, B, and Zr.
2. The nickel-base superalloy composition as in claim 1 , the elements that form low-melting eutectics are not bound in precipitates, and form low-melting eutectics.
3. The nickel-base superalloy composition as in claim 2 , said first elements include Hf in the range 1.2 wt-%<Hf<5 wt-%.
4. The nickel-base superalloy composition as in claim 3 , said first elements include Hf in the range 1.6 wt-%<Hf<3.5 wt-%.
5. The nickel-base superalloy composition as in claim 4 said first elements include Hf in the range 1.7 wt-%<Hf<2.8 wt-%.
6. The nickel-base superalloy composition as in claim 2 , wherein Hf/C ratio >1.91.
7. The nickel-base superalloy composition as in claim 6 , wherein C >0.01 wt-% for grain boundary strengthening.
8. The nickel-base superalloy composition as claim 7 , wherein 0.01 wt-%<C<0.2 wt-%.
9. A nickel-base superalloy composition-comprising a γ/γ′-microstructure with a chemical composition of (in wt. %):
10.0 W,
10.0 Co,
8.4 Cr,
5.5 Al,
3.0 Ta,
2.4 Hf,
1.0 Ti,
0.7 Mo,
0.15 C,
0.05 Zr,
0.015 B, and
balance Ni,
wherein cracking susceptibility is reduced by controlling an amount of elements that form low-melting eutectics, and wherein the elements that form low-melting eutectics include at least one of Hf, B, and Zr.
10. The nickel-base superalloy composition as in claim 9 , wherein said first elements include Hf in the range 1.2 wt-%<Hf<5 wt-%.
11. The nickel-base superalloy composition as in claim 10 said first elements include Hf in the range 1.6 wt-%<Hf<3.5 wt-%.
12. The nickel-base superalloy composition as in claim 11 , wherein said first elements Hf in the range 1.7 wt-%<Hf<2.8 wt-%.
13. The nickel-base superalloy composition as in claim 11 , wherein Hf/C ratio >1.91.
14. The nickel-base superalloy composition as in claim 9 , wherein 0.01 wt-%<C<0.2 wt-%.