In the present work, 6082 Al alloy has been rolled to 40% and 70% thickness reductions at the cryogenic and room temperatures for the improvement in mechanical and fracture toughness properties. All cryorolled samples...In the present work, 6082 Al alloy has been rolled to 40% and 70% thickness reductions at the cryogenic and room temperatures for the improvement in mechanical and fracture toughness properties. All cryorolled samples are subjected to aging at different temperatures, i.e., 140, 160, and 190 ℃ to improve the strength, ductility, and fracture toughness. The microstructures of the cryorolled （CR） and room temperature rolled （RTR） alloy after 40% and 70% thickness reductions are characterized by FE-SEM to reveal the modes of failure. The results show that the starting bulk Al alloy specimen is fractured in total ductile manner, consisting of well-developed dimples over the entire surface. The mechanical properties and fracture toughness of the 70% CR alloy are found better than 70% RTR alloy due to higher dislocations density and formation of sub-grain structures in the CR alloy.展开更多
This work aims at evaluating the mechanical behavior of sisal fiber reinforced cement mortar. The composite material was produced from a mixture of sand, cement, and water. Sisal fibers were added to the mixture in di...This work aims at evaluating the mechanical behavior of sisal fiber reinforced cement mortar. The composite material was produced from a mixture of sand, cement, and water. Sisal fibers were added to the mixture in different lengths. Mechanical characterization of both the composite and the plain mortar was carried out using three point bend, compression, and impact tests. Specimens containing notches of different root radii were loaded in three point bending in an effort to determine the effect of the fibers on the fracture toughness of the material. The results obtained indicate that, while fiber reinforcement leads to a decrease in compressive strength, J-integral calculations at maximum load for the different notch root radii have indicated, particularly for the case of long fibers, a significant superiority of the reinforced material in comparison with the plain cement mortar, in consistence with the impact test data.展开更多
It is of practical importance to establish the relationship between intensity andtoughness parameters and porosity of porous materials. This is of benefit not onlyto the development of powder metallurgy but to the dam...It is of practical importance to establish the relationship between intensity andtoughness parameters and porosity of porous materials. This is of benefit not onlyto the development of powder metallurgy but to the damage mechanics theoryas well. Porous materials can be separated into two types according to the properties ofvoids distribution, i.e. the simple porous materials and the complicated porous materi-als. The voids for the former are completely random in shape, size, and distribution,and therefore, these porous materials are homogenous and isotropic in macroscopicscale from the statistical viewpoint. Conversely, the voids for the latter are not ran-展开更多
文摘In the present work, 6082 Al alloy has been rolled to 40% and 70% thickness reductions at the cryogenic and room temperatures for the improvement in mechanical and fracture toughness properties. All cryorolled samples are subjected to aging at different temperatures, i.e., 140, 160, and 190 ℃ to improve the strength, ductility, and fracture toughness. The microstructures of the cryorolled （CR） and room temperature rolled （RTR） alloy after 40% and 70% thickness reductions are characterized by FE-SEM to reveal the modes of failure. The results show that the starting bulk Al alloy specimen is fractured in total ductile manner, consisting of well-developed dimples over the entire surface. The mechanical properties and fracture toughness of the 70% CR alloy are found better than 70% RTR alloy due to higher dislocations density and formation of sub-grain structures in the CR alloy.
文摘This work aims at evaluating the mechanical behavior of sisal fiber reinforced cement mortar. The composite material was produced from a mixture of sand, cement, and water. Sisal fibers were added to the mixture in different lengths. Mechanical characterization of both the composite and the plain mortar was carried out using three point bend, compression, and impact tests. Specimens containing notches of different root radii were loaded in three point bending in an effort to determine the effect of the fibers on the fracture toughness of the material. The results obtained indicate that, while fiber reinforcement leads to a decrease in compressive strength, J-integral calculations at maximum load for the different notch root radii have indicated, particularly for the case of long fibers, a significant superiority of the reinforced material in comparison with the plain cement mortar, in consistence with the impact test data.
文摘It is of practical importance to establish the relationship between intensity andtoughness parameters and porosity of porous materials. This is of benefit not onlyto the development of powder metallurgy but to the damage mechanics theoryas well. Porous materials can be separated into two types according to the properties ofvoids distribution, i.e. the simple porous materials and the complicated porous materi-als. The voids for the former are completely random in shape, size, and distribution,and therefore, these porous materials are homogenous and isotropic in macroscopicscale from the statistical viewpoint. Conversely, the voids for the latter are not ran-
