| As a metal material with low price and excellent comprehensive performance,6061 aluminum alloy is widely used in many industrial manufacturing fields.At present,the rapid progress of technology and the continuous development of industry have put forward more and more high requirements for the performance and service life of metal materials under harsh environmental conditions,and how to effectively improve the strength and fatigue resistance of metal materials has become an important issue.In recent years,due to its high efficiency and convenience,ultrasonic impact treatment technology has become a mechanical surface strengthening technology for materials with a wider range of applications from the improvement of fatigue performance of welded joints.Based on existing processing equipment,this paper carried out basic experimental research on ultrasonic impact surface strengthening of 6061 specimen,the main research content is as follows:1? Design and manufacture the main components of ultrasonic impact vibration system.Based on the theoretical analysis and calculation,the ultrasonic transducer and the integrated amplitude transformer used in the test were designed and manufactured.At the same time,the vibration performance of the vibration system was tested with the help of relevant instruments,and the exact impedance and amplitude parameters of the system were obtained.2?The test platform was constructed to carry out the strengthening process test and the simulation analysis of the test process was carried out.Clear test principle and main technical parameters,and the test platform which can automatically control the machine tool based on the equivalent impedance of the system is constructed,and design the corresponding orthogonal experiment scheme,and the finite element simulation of the impact test process under the same parameters is carried out,explores the impact of treated specimen material surface residual stress field distribution..3?The surface residual stress and related microstructure properties of the specimen after ultrasonic impact treatment were tested and the strengthening mechanism of ultrasonic impact on the material was analyzed.The test results show that the residual compressive stress is formed on the surface of the material after impact treatment,and the impact amplitude has the most significant effect on the stress value.The surface hardness of the material increased obviously,the grain was refined,the microstructure became compact,and the hardened layer was formed.The fatigue life of the specimens is increased and the fatigue resistance is improved. |
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