Influence of experimental variables on fracture toughness determined on SEVNB in three points bending. Mullite a case study |
| |
| Authors: | A García-Prieto C Baudín |
| |
| Affiliation: | 1. Department of Materials Science and Metallurgy, Universitat Politécnica de Catalunya, Av. Diagonal 647 (ETSEIB), 08028 Barcelona, Spain;2. Center for Research in Nano-engineering, CRNE, C. Pascual i Vila, 15, 08028 Barcelona, Spain;1. School of Materials Science and Engineering, University of Shanghai for Science & Technology, Shanghai, 200093, China;2. School of Mechanical Engineering, Xiangtan University, Xiangtan, Hunan, 411105, China;1. Engineering Ceramic Department, Korea Institute of Materials Science, 797 Changwondaero, Seongsan-gu, Changwon 642-831, Gyeongnam, Republic of Korea;2. University of Science & Technology, 217 Gajeong-ro, Yuseong-gu, Daejeon 305-350, Republic of Korea;1. School of Materials, University of Manchester, Manchester M13 9PL, UK;2. Technology and Engineering Centre for Space Utilisation, Chinese Academy of Science, Beijing 10094, PR China;1. Nuclear Power Institute of China, Science and Technology on Reactor System Design Technology Laboratory, Chengdu, 610200 China;2. School of Materials Science and Engineering, Harbin Institute of Technology, Harbin, 150001 China |
| |
| Abstract: | The effect of testing variables on toughness of single edge “V” notched beams (4 mm × 6 mm × 50 mm, α = 0.6) of a fine grained mullite (d50 = 0.7 ± 0.5 μm) in three points bending (span = 40 mm) is analysed. Mullite was selected as case material because it presents flat R-curve and subcritical crack propagation. Stable fracture was reached by using the CMOD as control variable (0.001 and 0.018 mm/min). Results for stable test and unstable displacement (0.05 mm/min) controlled tests are analysed. KIC has been calculated from maximum loads, KICp, and from the total fracture energy determined in stable tests, KICγ. The fact that for materials with flat R-curve both KIC values are coincident has been used as criterion for adequacy of the test. Stable fracture at high deformation rates is required to fulfil KICp = KICγ. Under such conditions, an intrinsic KIC = 0.86 ± 0.06 MPa m1/2, less than one half of those previously reported has been obtained. |
| |
| Keywords: | |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
