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为提高2024HDT-T351新型铝合金的抗疲劳性能,采用陶瓷丸喷丸新技术研究了喷丸强度、覆盖率及表面完整性对2024HDT-T351铝合金疲劳性能的影响,利用X射线应力仪、粗糙度仪、扫描电子显微镜(SEM)、显微硬度计等,分析了喷丸强化对铝合金表面残余应力场、表面粗糙度、表面损伤及表面加工硬化的影响,以及疲劳抗力的作用机制。结果表明:在高周疲劳试验条件下,合理参数的喷丸强化处理能够有效改善铝合金的表面完整性,显著提高铝合金的疲劳抗力,而过高强度或覆盖率的喷丸处理则不利于铝合金的表面完整性,因而不能有效改善铝合金的疲劳性能;在近低周疲劳试验条件下,高交变应力使喷丸引入的表层残余压应力严重松弛,喷丸引入的不利因素(粗糙度增大和组织损伤等)与有利因素的作用彼此抵消,此时喷丸处理不能有效改善铝合金的疲劳性能。
In order to improve the fatigue resistance of 2024HDT-T351 aluminum alloy, the effect of shot peening strength, coverage and surface integrity on the fatigue properties of 2024HDT-T351 aluminum alloy was studied by using the new technology of ceramic shot peening. The X-ray stress gauge, The effects of shot peening on residual stress field, surface roughness, surface damage and surface work hardening of aluminum alloy and the mechanism of fatigue resistance were analyzed. The results show that under the conditions of high cycle fatigue test, shot peening with proper parameters can effectively improve the surface integrity of the aluminum alloy and significantly improve the fatigue resistance of the aluminum alloy. However, shot peening with too high strength or coverage is unfavorable Aluminum alloy surface integrity, and thus can not effectively improve the fatigue performance of aluminum alloy; in the near low cycle fatigue test conditions, the high alternating stress so that the shot peening surface residual compressive stress serious relaxation, the peening of the adverse factors (rough Degree of increase and tissue damage, etc.) and the role of favorable factors offset each other, this time shot peening can not effectively improve the fatigue properties of aluminum alloys.