Achieving high strength and ductility in ODS-W alloy by employing oxide@W core-shell nanopowder as precursor

Abstract

With excellent creep resistance, good high-temperature microstructural stability and good irradiation resistance, oxide dispersion strengthened (ODS) alloys are a class of important alloys that are promising for high-temperature applications. However, plagued by a nerve-wracking fact that the oxide particles tend to aggregate at grain boundary of metal matrix, their improvement effect on the mechanical properties of metal matrix tends to be limited. In this work, we employ a unique in-house synthesized oxide@W core-shell nanopowder as precursor to prepare W-based ODS alloy. After low-temperature sintering and high-energy-rate forging, high-density oxide nanoparticles are dispersed homogeneously within W grains in the prepared alloy, accompanying with the intergranular oxide particles completely disappearing. As a result, our prepared alloy achieves a great enhancement of strength and ductility at room temperature. Our strategy using core-shell powder as precursor to prepare high-performance ODS alloy has potential to be applied to other dispersion-strengthened alloy systems.

The Influence of Coherent Oxide Interfaces on the Behaviors of Helium (He) Ion Irradiated ODS W

“…The interplanar spacing of coherent oxide particles labeled by red dashed circles is 3.34 Å, which is slightly larger than the measured interplanar spacing of {110} plane (3.23 Å) of sounding matrix, indicating negligible lattice mismatch of oxide particle and matrix. Furthermore, the chemical composition and density of nanoparticles are revealed according to the atom probe tomography reported in the previous work [ 26 ]. The atom ratio of W and Y is about 1:1, and the density of nanoparticles is 1.953 × 10 24 per m 3 .…”

“…This resulted in the uniform dispersion of high-density oxide nanoparticles within the W grains interior and fully coherent with the W matrix in the prepared alloy. Detailed information on the preparation process of the ODS-W alloy can be seen elsewhere [ 26 ].…”

“…Introducing the particles with full coherency with matrix, ultrafine grain size, and completely intragranular distribution has become the key and hot topic to further develop high-performance second-phase particles strengthened alloys, and has been successfully achieved in multiple systems such as steel [ 22 , 23 ] and high entropy alloys [ 24 , 25 ]. Our previous research proposed a unique strategy using in-house synthesized Y 2 O 3 core–shell nanopowder as a precursor to prepare W-based ODS alloy [ 26 ]. High-density oxide nanoparticles are dispersed homogeneously within W grains and present full lattice coherency with the surrounding W matrix in the prepared alloy.…”

A green method for preparing mechanically robust poly(propylene carbonate) with full biodegradability via incorporating hybrid natural filler

“…Environmental issues, such as petroleum exhaustion and plastic pollution, have been attracting a great deal of attention in recent years 1–3 . Poly(propylene carbonate) (PPC), a carbon dioxide (CO 2 )/propylene oxide copolymer, is a promising sustainable polymer material due to merits such as full biodegradability and transforming renewable CO 2 into polymer 4,5 .…”

In Situ Observation of the Atomic-scale High-temperature Phase Transition Enhancement Mechanism at the ODS-W Interface

“…Given that oxide particles are mostly located at grain boundaries, the increase in heterogeneous phases often acts as a source of cracks. Thus, many researchers currently attempt to dissolve particles completely in the crystal, the W-X alloy that is dissolved in the crystal improves the toughness of pure W at room temperature; however, the ODS alloy exhibits an excellent tensile strength at high temperatures 18 , and the author could not clearly explain this phenomenon; the superb performance at high temperatures is believed to be due to fine grain strengthening. Owing to the exponential increase of the tensile strength of ODS alloy at high temperatures, the strengthening mechanism of ODS alloy should include fine-grain strengthening and traditional second-phase strengthening, and other strengthening methods.…”