微观孔洞对铝合金压铸件疲劳性能的影响

发布时间：2018-12-28 16:48

【摘要】：基于高分辨率三维X射线断层扫描技术,对实际ADC12铝合金压铸件疲劳试样内部微观孔洞进行了检测和重构,对7组不同孔隙率的试样进行了5级应力水平的高周疲劳实验。三参数Weibull分析表明:随着应力水平升高,疲劳寿命分散性逐渐降低。采用SEM观察疲劳断口,确定诱发疲劳裂纹起源的孔洞,并对其进行了分析;基于断口表面的孔洞特征以及X射线断层扫描重构数据,建立了孔洞-疲劳寿命预测方程,并与实验结果进行了对比分析。将三维X射线断层扫描重构数据与有限元分析相结合,计算和分析了实际微观孔洞引起的应力情况,为研究材料内部实际微观孔洞特征对性能的影响提供新的途径。
[Abstract]:Based on the high resolution 3D X-ray scanning technique, the internal microvoids of ADC12 aluminum alloy die castings were examined and reconstructed. Seven groups of specimens with different porosity were tested with high cycle fatigue at five stress levels. Three-parameter Weibull analysis shows that the dispersion of fatigue life decreases with the increase of stress level. SEM was used to observe the fatigue fracture surface to determine the origination of the fatigue crack and to analyze it. Based on the pore characteristics of the fracture surface and the data of X-ray tomography reconstruction, the void-fatigue life prediction equation is established and compared with the experimental results. By combining the reconstruction data of 3D X-ray tomography with the finite element analysis, the stress caused by the actual micro-voids is calculated and analyzed, which provides a new way to study the effect of the characteristics of the microvoids inside the materials on the properties.
【作者单位】：华南理工大学国家金属材料近净成形工程技术研究中心;
【基金】：国家高技术研究发展计划资助项目(2013AA031201) 教育部新世纪优秀人才支持计划项目(NCET-08-0209) 中央高校基本科研业务费项目(2012ZP0006)
【分类号】：TG146.21;TG115

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