摘要
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 the new aluminum alloy 2024HDT-T351, the influence of shot peening intensity, coverage and surface integrity on the fatigue properties of 2024HDT-T351 aluminum alloy was studied by ceramic peening. The effect of shot peening on surface characteristics, including residual stress, roughness, damage and hardness, was analyzed by X-ray stress instrument, roughness tester, scanning electron microscopy （SEM）, microhardness instrument, etc. The mechanism of fatigue resistance improvement by shot peening was also discussed. The results show that the reasonable parameter of shot peening can improve the surface integrity of 2024HDT-T351 effectively, as well as fatigue resistance. However, under high cycle fatigue, much too higher peening intensity or coverage is adverse to surface integrity and fatigue resistance. In near-low cycle conditions, severe relaxation of residual compressive stress due to high stress, unfavorable factors （roughness and microstructure damage） occurs, the effect of favorable factors will be neglected, therefore, fatigue properties of 2024HDT-T351 are unable to be improved by shot peening.
出处
《兵器材料科学与工程》
CAS
CSCD
北大核心
2014年第4期15-20,共6页
Ordnance Material Science and Engineering
基金
国家自然科学基金(51171154)
