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Refined Microstructure and Enhanced Mechanical Properties of 93W–4.9Ni–2.1Fe–1La2O3 Alloy Fabricated by a Two-Stage Sintering Process.
- Source :
- Metallurgical & Materials Transactions. Part A; Dec2022, Vol. 53 Issue 12, p4404-4420, 17p
- Publication Year :
- 2022
-
Abstract
- In this work, high-performance 93W–4.9Ni–2.1Fe–1La<subscript>2</subscript>O<subscript>3</subscript> (wt pct) alloy was fabricated by a two-stage sintering method and subsequent vacuum heat-treatment, which had a high densification degree (99.4 pct) and fine grain sizes of W (only 9.76 μm). The utilization of ultrafine W–Ni–Fe composite powder, addition of La<subscript>2</subscript>O<subscript>3</subscript> particles and optimized sintering technique effectively resulted in structure refinement. Moreover, the second-phase particles were mainly dispersed at grain boundaries (GBs), besides a small amount of them in the interior of W grains. The as-prepared alloys after sintering first at 1400 °C for 2 hour and then at 1500 °C 30 minutes exhibited enhanced mechanical properties, with a maximum tensile strength of ~ 1024 MPa, elongation of ~ 22.7 pct and hardness of ~ 457 HV<subscript>1</subscript>. The excellent strength could be attributed to various mechanisms, namely fine-grained strengthening and oxide dispersion strengthening. Meanwhile, the ductilization is predominantly benefitted from a synergistic effect of low angle grain boundaries, intragranular oxide particles and vacuum heat-treatment process. This work not only promotes the development of oxide-reinforced WHAs for challenging engineering applications but also provides a new perspective for the design of refractory composite materials. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 10735623
- Volume :
- 53
- Issue :
- 12
- Database :
- Complementary Index
- Journal :
- Metallurgical & Materials Transactions. Part A
- Publication Type :
- Academic Journal
- Accession number :
- 160140367
- Full Text :
- https://doi.org/10.1007/s11661-022-06835-7