Effect of hot-working process on interface structure and ductile-to-brittle transition temperature of tungsten alloy reinforced by Al2O3 particles. (November 2022)

• Record Type: Journal Article
• Authors: Wang, Changji; Dong, Xiaonan; Wei, Shizhong; Yu, Hua; Pan, Kunming; Chen, Chong; Xiong, Mei; Mao, Feng; Cui, Hailin; Xiao, Liqiang; Dong, Zhili; Wang, Shu
• Is Part Of: International journal of refractory metals & hard materials. Volume 108(2022)
• Publication Date: 2022-11
• Subjects: Tungsten -- Interface characteristics -- Ductile-to-brittle transition temperature -- 3-point bending tests -- Composite materials; Heat resistant alloys -- Periodicals; Refractory materials -- Periodicals; Metallography -- Periodicals; Alliages réfractaires -- Périodiques; Matériaux réfractaires -- Périodiques; Métallographie -- Périodiques; Heat resistant alloys; Metallography; Refractory materials; Periodicals; Electronic journals; 669.73
• DOI: 10.1016/j.ijrmhm.2022.105945
• Languages: English
• ISSNs: 0263-4368

Abstract

Abstract: The W-0.25 wt%Al2 O3 alloy was fabricated by a powder metallurgy processing route, including hydrogen reduction, induction sintering and hot swaging. Al2 O3 particles are absorbed on the surface of W particles with size ranging from 50 to 1000 nm. The microstructure of sintered alloy presents equiaxed grains with an average size of 8.6 μm and TEM result shows that a semi-coherent relationship exists in between W and Al2 O3 . After swaging, the swaged W-0.25 wt%Al2 O3 alloy with fully dense was obtained. EBSD result indicates most of grains are obviously elongated and the average aspect ratio of W grains is 2.3:1. There is an obvious transition layer with a thickness of approximately 20 nm between W and Al2 O3 . The interface displays an amorphous feature because of uncoordinated deformation occurred in swaging process. 3-point bend tests show that the ductile-to-brittle transition temperature of sintered alloy is in the range of 350–400 °C. Moreover, the swaged alloy begins to exhibit obvious ductile behavior at 100–200 °C and the bending strength increases with increasing temperature, which reaches a maximum value of 1762 MPa at 400 °C. Highlights: A semi-coherent relationship exists in sintered W-0.25 wt%Al2 O3 alloy between 1 ¯ 1 ¯ 0 W and 2 ¯ 42 Al 2 O 3 . An obvious transition layer with a thickness of 20 nm exits in the interface after swaging. The ductile-to-brittle transition temperature of swaged alloy is 100–200 °C. The specimen was bent into a near "U" shape without failure, which reaches a maximum value of 1762 MPa at 400 °C.