In-situ SEM observation of fracture toughness tests has been used to characterize the fracture behavior of a wrought aluminum alloy. Particular attention is given to in-situ fracture strength of the coarse inclusions associated with this alloy. The fracture domain of CuAl2 and Al2CuMg particles with respect to the main crack is also investigated. Crack propagation is conducted by ductile failure of matrix ligaments between the fractured particles and the main crack, thereby producing slight crack deflection. Coarse Al3Zr and Al3Ti particles even adjacent to the fracture surface remain intact, while CuAl2 and Al2CuMg particles are extensively damaged ahead of a crack-tip. A combination of HRR singularity and Eshelby type internal stress analysis is used to estimate the in-situ strength values of various inclusion particles. It is concluded that the fracture strength of the inclusion particles has strong dependence on diameter. For example, it decreases from 740 to 500 MPa for the Al2CuMg. By decreasing the volume fraction of the coarse inclusions larger than 3μm from 2.2 to 1.2% by applying various heat and thermo-mechanical treatments, 0.2% proof stress, fracture toughness and crack propagation resistance of the alloy are remarkably improved without sacrificing ductility.
|ジャーナル||Materials Science Forum|
|出版ステータス||出版済み - 2000|
|イベント||The 7th International Conference ICCA7 - 'Aluminium Alloys: 'Their Physical and Mechanical Properties' - Charlottesville, VA, USA|
継続期間: 4月 9 2000 → 4月 14 2000
!!!All Science Journal Classification (ASJC) codes