1. Comparative study on microstructure and performance of sintered, forged and annealed W-3Re-HfC composites.
- Author
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Liu, Meng, Liu, Xueshan, Liu, Wenlong, Zhao, Ximeng, Li, Rong, Song, Jiupeng, Sun, Benzhe, and Qi, Yang
- Subjects
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TENSILE strength , *POWDER metallurgy , *DISPERSION strengthening , *SPECIFIC gravity , *GRAIN refinement , *CRYSTAL grain boundaries - Abstract
By the powder metallurgy, as well as subsequent forging and annealing processes, a series of W-3Re-HfC (WRH) composites were fabricated successively. Microstructure and performance of WRH composites were investigated comparatively. It is found that the sintered, forged and annealed WRH composites are consistently made up of W-Re matrix, HfO 2 and HfC second phase particles. The larger HfO 2 particle is derived from the oxidation of HfH 2 powder, playing an important role in purifying grain boundary and refining grain of matrix. The smaller HfC particle inside W-Re grains has a dispersion reinforcement effect. The forged WRH composites can obtain the highest relative density (99.9%), the micro-hardness (534.1 HV) and ultimate tensile strength (758 MPa), which is ascribed to the refinement of grains and dispersion strengthening. Although the performance of annealed WRH composites has a slight drop, an excellent interfacial matching between second phase particles and W-Re matrix can be produced, which facilitates to gain a better interfacial strength and homogenized microstructure. • Composites are composed of W-Re matrix, HfO 2 and HfC second phase particles. • The HfO 2 particle can effectively purify and pin the grain boundary. • Composites after forging can obtain superior micro-hardness and tensile strength. • Composites annealed at 1700 °C can yield an excellent interface strength. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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