Amorphization–Densification Coupling Governs Hardness Enhancement in SPS-Consolidated Al–Fe–Nb–(Ni,Ti) Metastable Alloys.
Saved in:
| Title: | Amorphization–Densification Coupling Governs Hardness Enhancement in SPS-Consolidated Al–Fe–Nb–(Ni,Ti) Metastable Alloys. |
|---|---|
| Authors: | Oanh, Nguyen Thi Hoang1 (AUTHOR), Viet, Nguyen Hoang1 (AUTHOR) viet.nguyenhoang@hust.edu.vn |
| Source: | Materials (1996-1944). Jun2026, Vol. 19 Issue 12, p2628. 19p. |
| Subjects: | Hardness, Sintering, Compacting, High-entropy alloys, Glass structure, Alloys, Mechanical alloying, Nanocomposite materials |
| Abstract: | Highlights: Nb, Ni, and Ti additions progressively promote amorphization in the mechanically alloyed Al82Fe14−xNb2(Ni/Ti)x system. The quinary Al82Fe12Nb2Ni2Ti2 alloy shows the strongest amorphization tendency, driven by higher ΔSmix and more negative ΔHmix. SPS at 500 °C yields amorphous–nanocrystalline composites containing Al13Fe4 and Al3Nb nanophases. Maximum hardness (445.4 HV) is achieved in Al82Fe14Nb2Ni2, not in the most amorphous alloy. Hardness response requires kinetic balance between amorphous retention, nanocrystallization, and densification efficiency. The coupled effects of Ni and Ti additions on amorphization, spark plasma sintering (SPS) response, and hardness evolution were investigated in Al-rich Al–Fe–Nb-based metastable alloys. Mechanically alloyed Al82Fe14Nb2Ni2, Al82Fe14Nb2Ti2, and Al82Fe12Nb2Ni2Ti2 powders showed progressive loss of long-range order, with the quinary alloy exhibiting the strongest amorphization tendency, consistent with its higher configurational entropy (5.420 J·mol−1·K−1) and more negative mixing enthalpy (−9.36 kJ·mol−1). SPS displacement analysis revealed that primary displacement contribution occurs during heating and is progressively limited by crystallization-induced stiffening. Consolidation at 500 °C produced amorphous–nanocrystalline composites containing Al13Fe4 and Al3Nb, whereas increasing the temperature to 550 °C promoted further devitrification. The highest hardness, 445.4 HV, was obtained for Al82Fe14Nb2Ni2, despite its lower amorphous-forming ability than the quinary alloy. This demonstrates that hardness is controlled not by maximum amorphization, but by the kinetic balance between amorphous retention, fine intermetallic precipitation, and densification efficiency. The results identify SPS as a coupled densification–transformation route for designing high-strength Al-based amorphous–nanocrystalline alloys. [ABSTRACT FROM AUTHOR] |
| Copyright of Materials (1996-1944) is the property of MDPI and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.) | |
| Database: | Engineering Source |
|
Full text is not displayed to guests.
Login for full access.
|
|
| Abstract: | Highlights: Nb, Ni, and Ti additions progressively promote amorphization in the mechanically alloyed Al82Fe14−xNb2(Ni/Ti)x system. The quinary Al82Fe12Nb2Ni2Ti2 alloy shows the strongest amorphization tendency, driven by higher ΔSmix and more negative ΔHmix. SPS at 500 °C yields amorphous–nanocrystalline composites containing Al13Fe4 and Al3Nb nanophases. Maximum hardness (445.4 HV) is achieved in Al82Fe14Nb2Ni2, not in the most amorphous alloy. Hardness response requires kinetic balance between amorphous retention, nanocrystallization, and densification efficiency. The coupled effects of Ni and Ti additions on amorphization, spark plasma sintering (SPS) response, and hardness evolution were investigated in Al-rich Al–Fe–Nb-based metastable alloys. Mechanically alloyed Al82Fe14Nb2Ni2, Al82Fe14Nb2Ti2, and Al82Fe12Nb2Ni2Ti2 powders showed progressive loss of long-range order, with the quinary alloy exhibiting the strongest amorphization tendency, consistent with its higher configurational entropy (5.420 J·mol−1·K−1) and more negative mixing enthalpy (−9.36 kJ·mol−1). SPS displacement analysis revealed that primary displacement contribution occurs during heating and is progressively limited by crystallization-induced stiffening. Consolidation at 500 °C produced amorphous–nanocrystalline composites containing Al13Fe4 and Al3Nb, whereas increasing the temperature to 550 °C promoted further devitrification. The highest hardness, 445.4 HV, was obtained for Al82Fe14Nb2Ni2, despite its lower amorphous-forming ability than the quinary alloy. This demonstrates that hardness is controlled not by maximum amorphization, but by the kinetic balance between amorphous retention, fine intermetallic precipitation, and densification efficiency. The results identify SPS as a coupled densification–transformation route for designing high-strength Al-based amorphous–nanocrystalline alloys. [ABSTRACT FROM AUTHOR] |
|---|---|
| ISSN: | 19961944 |
| DOI: | 10.3390/ma19122628 |
