http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
- 中文 을 입력하시려면 zhongwen을 입력하시고 space를누르시면됩니다.
- 北京 을 입력하시려면 beijing을 입력하시고 space를 누르시면 됩니다.
RISS 인기검색어
- 검색키워드
- 저자 : Jiaojiao Yi (검색결과 5 건)
- 무료
- 기관 내 무료
- 유료
-
Jiaojiao Yi,Lin Yang,Lu Wang,Mingqin Xu 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.7
The phase component, microstructure, and compressive properties of a novel 3d transition metal high entropy alloy, CoCuNiTiV, derived from Fe replaced by V in CoCuNiTiFe alloy, were evaluated in as-cast and annealed conditions. The experiments showed that the as-cast alloy possessed a typical BCC+FCC dual-phases, which distinctly varied from the singleFCC phase of an adjacent CoCuNiTiFe alloy. The BCC phase takes up the majority acting as the matrix, in which Cu wasdepleted, and the other elements (i.e., Co, Ni, Ti, and V) were distributed homogenously. Meanwhile, the FCC phase wasCu-rich, and sandwiched in the interval space between the BCC phases forming a net-like framework. After annealing, thematrix bifurcated into two parts: (i) one that remained as the primary BCC phase and (ii) another that decomposed into aCo2Ti-type laves phase and a new BCC phase. Meanwhile, the Cu-rich net-like framework is deteriorated forming a seriesof evenly distributed particles. The yield strength and the fracture strength of the as-cast and annealed alloy are highlysimilar— about 1674 and 2400 MPa, respectively. The hardness of the annealed alloy (572.9±10.6 HV) was slightly higherthan that of the as-cast alloy (530.3±12.2 HV).
-
Jiaojiao Yi,Lin Yang,Lu Wang,Mingqin Xu,Lisha Liu 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.1
A novel 3d transition metal high entropy alloy (TM HEA), CrCuFeTiV, was fabricated by arc-melting under a vacuum condition. Its phase component, microstructure, and compressive properties in the as-cast and annealed conditions were carefullyinvestigated. The experimental results showed that the alloys in both conditions consist of one BCC phase (CrV/FeTi-richregions), one FCC phase (Cu-rich), and one hexagonal Laves phase (Cr2Ti). It is suggested that the CrV-rich BCC phasepreferentially separates as dendritic centers. Subsequently, the Cr2Ti Laves phase and the FeTi-rich BCC phase solidify as adendritic outer layer. Finally, the FCC Cu-rich phase is squashed into the remaining interdendritic regions. Besides, the yieldstrength, ultimate strength, and hardness of the as-cast CrCuFeTiV alloy are 1686 MPa, 2205 MPa, and 624 HV, while thosefor the annealed alloy are 1510 MPa, 2035 MPa, and 618 HV, respectively. The obtained values are the highest among thetabulated fve-principle equiatomic Cu-containing 3d TM HEAs. The promising strength-hardness synergy of CrCuFeTiValloy is likely originated from the majority constitution of the BCC phase and Cr2Ti Laves phase.
-
Lightweight, Refractory High-Entropy Alloy, CrNbTa0.25TiZr, with High Yield Strength
Jiaojiao Yi,Lin Yang,Lu Wang,Mingqin Xu 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.2
A new lightweight, refractory high entropy alloy (HEA), CrNbTa0.25TiZr,was prepared by arc-melting under a vacuumcondition. The as-cast and annealed CrNbTa0.25TiZrpossessed identical dual-phase components: a BCC + a cubic Lavesphase. After annealing, the Laves phase matrix in the as-cast alloy was replaced by the BCC phase, possibly due to the diffusionof Cr, which have a much smaller atomic radius than the other principal elements. From a performance perspective,the yield strength significantly increased from 926 MPa of the as-cast HfNbTaTiZr to 1800 MPa and 1500 MPa for as-castand annealed CrNbTa0.25TiZr,while its density (7.25 g/cm3) is only 73% of HfNbTaTiZr. The microstructure evolution ofthe stiff cubic Laves phase is highlighted to unveil the promising strength of the CrNbTa0.25TiZr.
-
Lu Wang,Xia Li,Hongwei Niu,Lin Yang,Mingqin Xu, Jiaojiao Yi 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.10
Cr was used to replace Nb, Ti, and Zr in a precursor alloy HfMoNbTiZr, and its effect on the microstructure, phase constitution,and mechanical properties of the newly formed alloys were investigated. Microstructural evolutions revealed thata cubic Laves phase emerged regardless of which element was substituted by Cr. The original single-phase BCC structureof the precursor alloy was thus deteriorated and replaced by two BCC and one cubic Laves phases. The formation of theLaves phase and BCC phases increased the strength to 2480 ± 40 MPa in the HfMoNbTiCr alloy, while the net-like structure(Laves phase) impeded the crack extension and compensated for the decreased plasticity due to the introduction of thebrittle-stiff Laves phase. The other two alloys, HfMoTiZrCr and HfMoNbZrCr, possessed lower strengths of 1400 ± 20 and1642 ± 23 MPa and exhibited a completely brittle fracture character, which was attributed to the high volume fraction andthe morphologies of the Laves phase.
-
Study on Microstructure and Mechanical Properties of CrCuFeNiV Multi Principal Element Alloy
Lu Wang,Zhengzhong Feng,Hongwei Niu,Qi Gao,Mingqin Xu,Lin Yang,Jiaojiao Yi 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.12
Phase constitution, microstructure, and mechanical properties of the as-cast and homogenized CrCuFeNiV multi principalelement alloys were investigated. Results show that the microstructures of CrCuFeNiV alloys either in the as-cast orhomogenized state were constituted by the dispersed Cu-rich fcc regions and the matrix regions (intertwined bcc + σ phases). Thereinto, the σ phase, ranged from nanometers to microns, was a complex multicomponent intermediate phase with a highsolubility for Fe, Cr, Ni, and V. This phase structure and hardness had an impressive thermal stability, which was evidencedby the current annealing treatment. High hardness (822 HV and 793 HV) was simultaneously achieved under an appliedload of 200 g in the as-cast and homogenized CrCuFeNiV alloys, on account of the incorporation of the high-stiffness σphase against the fcc and bcc phases. The ultimate compressive strength of ~ 1490 MPa was obtained in the as-cast alloydue to the high deformation resistance to the dislocation movement of bcc phase and precipitation strengthening of σ phaseat the expense of plasticity. The deterioration in plasticity was attributed to the stress concentration easily triggered by thehard and brittle σ phase.
연관 검색어 추천
이 검색어로 많이 본 자료
활용도 높은 자료
