The Influence Of Polishing Process On The Mechanical Properties Of An Aluminum Alloy Were Investigated Experimentally

With the continuous development of design concept on modern aircraft structure, constant application of new materials and new techniques, and the infiltration between different cross-cutting fields, materials research as the foundation of aviation production was received more and more attention from the nation.The various statics and fatigue fracture performance of materials are the basis of structure strength analysis, durability and damage tolerance design. To prevent the occurrence of catastrophic accident and ensure the safe reliability of aircraft structure, it needs to obtain accurate and efficient experimental data. Therefore the preparation process of specimen should authentically reflect various kinds of materials own mechanical properties and to eliminate the deviation of experimental data from production process. The stand or fall of the processing technique is the prerequisite of obtaining accurate experimental data At present, the common process route of production process on aluminum alloy mechanical properties specimen in China are CNC lathe turning first, and then using metallographic phase abrasive paper and polishing paste together to polishing the specimen work section with circumferential or tangential direction. However, a lot of scholar consider axial polishing to be a advanced polishing method.The research contents of this study are using different polishing technique to polish certain aluminum alloy specimen, study and analysis the relationship between polishing techniques and the performance parameters of statics strength (tension test at room temperature), axial fatigue and fracture (force controlled axial fatigue testing) and constant amplitude axial low-cycle fatigue test (strain-controlled fatigue testing). Through this research, further understood the influence from different processing techniques to mechanics of materials performance, found out the regularity results from analyzing parameters such as surface roughness, surface residual stress, fracture analysis, and mechanical property, determined the standard of production processing, and then in favor of formulation and execution of standard experimental method. The experimental results indicate that two different polishing techniques have no obvious difference to the static strength, low-cycle fatigue strength, and high-cycle fatigue strength of this aluminum alloy. There is no need to add axial polishing techniques to current specimen processing technique.The research provides a solution for the doubt which is better between radial and axial polishing methods. It also provides an important evidence using current radial polishing method for high polishing efficiency.