| Low cycle fatigue behaviors of pure Mo and Mo-La2O3 alloys | |
| Cheng, P. M.; Zhang, Z. J.; Zhang, G. J.; Zhang, J. Y.; Wu, K.; Liu, G.; Fu, W.; Sun, J.; Liu, G; Sun, J (reprint author), Xi An Jiao Tong Univ, State Key Lab Mech Behav Mat, Xian 710049, Shaanxi, Peoples R China. | |
| 2017-11-07 | |
| Source Publication | ELSEVIER SCIENCE SA
 |
| ISSN | 0921-5093 |
| Volume | 707Pages:295-305 |
| Abstract | Pure molybdenum (PM) and La2O3 dispersion strengthened Mo alloy (ODS-Mo) were prepared by powder metallurgy through two different mixing method (solid-solid or SS mixing and solid-liquid or SL mixing). After annealed at 1050 degrees C for 1 h, the PM, SS-Mo and SL-Mo were compared in microstructure and mechanical properties. The microstructural examinations showed that the PM was mostly recrystallized with rather coarse grains, but the ODS-Mo alloys remained fine elongated grains. This discrepancy is due to a higher re crystallization temperature held in the ODS-Mo alloys. The uniaxial testing results showed that the ODS-Mo had higher tensile mechanical properties compared to the PM, which are attributed to the remarkable strengthening and ductilizing effect induced by the La2O3 particles. The low cycle fatigue (LCF) testing results revealed that the PM experienced cyclic hardening behaviors, while the ODS-Mo alloys exhibited cyclic softening behaviors. The Basquin-Manson-Coffin analyses results demonstrated that the ODS-Mo possessed a higher fatigue ductility and longer fatigue life than the PM. Two kinds of cracks, i.e., cleavage cracks and intergranular cracks, were experimentally observed to coexist on the fracture surface. In particular in the SL-Mo alloy, the two crack interacted and propagated forward until final fracture, leading to a step-like crack growth path and concomitantly enhanced fatigue ductility. In addition, different cycling dislocation structures were revealed between the PM and ODS-Mo alloys. Cycle fatigue mechanisms responsible for the fatigue behaviors and microstructure evolution during LCF testing were discussed. The best LCF resistance combined with superior uniaxial tensile mechanical properties found in the SL-Mo alloy were rationalized.; Pure molybdenum (PM) and La2O3 dispersion strengthened Mo alloy (ODS-Mo) were prepared by powder metallurgy through two different mixing method (solid-solid or SS mixing and solid-liquid or SL mixing). After annealed at 1050 degrees C for 1 h, the PM, SS-Mo and SL-Mo were compared in microstructure and mechanical properties. The microstructural examinations showed that the PM was mostly recrystallized with rather coarse grains, but the ODS-Mo alloys remained fine elongated grains. This discrepancy is due to a higher re crystallization temperature held in the ODS-Mo alloys. The uniaxial testing results showed that the ODS-Mo had higher tensile mechanical properties compared to the PM, which are attributed to the remarkable strengthening and ductilizing effect induced by the La2O3 particles. The low cycle fatigue (LCF) testing results revealed that the PM experienced cyclic hardening behaviors, while the ODS-Mo alloys exhibited cyclic softening behaviors. The Basquin-Manson-Coffin analyses results demonstrated that the ODS-Mo possessed a higher fatigue ductility and longer fatigue life than the PM. Two kinds of cracks, i.e., cleavage cracks and intergranular cracks, were experimentally observed to coexist on the fracture surface. In particular in the SL-Mo alloy, the two crack interacted and propagated forward until final fracture, leading to a step-like crack growth path and concomitantly enhanced fatigue ductility. In addition, different cycling dislocation structures were revealed between the PM and ODS-Mo alloys. Cycle fatigue mechanisms responsible for the fatigue behaviors and microstructure evolution during LCF testing were discussed. The best LCF resistance combined with superior uniaxial tensile mechanical properties found in the SL-Mo alloy were rationalized. |
| description.department | [cheng, p. m. ; zhang, j. y. ; wu, k. ; liu, g. ; fu, w. ; sun, j.] xi an jiao tong univ, state key lab mech behav mat, xian 710049, shaanxi, peoples r china ; [zhang, z. j.] chinese acad sci, inst met res, shenyang natl lab mat sci, shenyang 110016, liaoning, peoples r china ; [zhang, g. j.] xian univ technol, sch mat sci & engn, xian 710048, shaanxi, peoples r china |
| Keyword | Molybdenum Rare Earth Oxide Addition Mechanical Properties Fatigue Behaviors Cycle Fatigue Mechanism |
| Subject Area | Nanoscience & Nanotechnology ; Materials Science, Multidisciplinary ; Metallurgy & Metallurgical Engineering |
| Funding Organization | National Natural Science Foundation of China [51621063, 51625103, 51571157]; 111 Project of China [B06025]; international Joint Laboratory for Micro/Nano Manufacturing and Measurement Technologies; Natural Science Basic Research Plan in Shaanxi Province of China [2015JM5158]; China Postdoctoral Science Foundation [2016M590940] |
| Indexed By | SCI |
| Language | 英语 |
| WOS ID | WOS:000414108200035 |
| Citation statistics | |
| Document Type | 期刊论文 |
| Identifier | http://ir.imr.ac.cn/handle/321006/78982 |
| Collection | 中国科学院金属研究所 |
| Corresponding Author | Liu, G; Sun, J (reprint author), Xi An Jiao Tong Univ, State Key Lab Mech Behav Mat, Xian 710049, Shaanxi, Peoples R China. |
| Recommended Citation GB/T 7714 | Cheng, P. M.,Zhang, Z. J.,Zhang, G. J.,et al. Low cycle fatigue behaviors of pure Mo and Mo-La2O3 alloys[J]. ELSEVIER SCIENCE SA,2017,707:295-305. |
| APA | Cheng, P. M..,Zhang, Z. J..,Zhang, G. J..,Zhang, J. Y..,Wu, K..,...&Sun, J .(2017).Low cycle fatigue behaviors of pure Mo and Mo-La2O3 alloys.ELSEVIER SCIENCE SA,707,295-305. |
| MLA | Cheng, P. M.,et al."Low cycle fatigue behaviors of pure Mo and Mo-La2O3 alloys".ELSEVIER SCIENCE SA 707(2017):295-305. |
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