铝合金熔焊区结构稳定性的测试技术

Structural stability measurement of fusion welding zones in aluminium alloys joints

在航空航天领域中,轻合金激光熔焊区的结构稳定性具有重要意义。因此,本文从晶界面结构视角具体审视这一问题。本研究以一种5系铝合金的激光熔焊区为研究对象,分别利用扫描电镜、电子背散射衍射(EBSD)和统计性的晶界面结构分析方法,首先实现了热影响区、等轴区和熔合区在空间上的准确划分;其次对各子区分别计算了穿过晶界面的取向差角分布情况;然后通过五参数法,对各子区内的晶界面进行了惯习面取向织构分析。基于上述工作,最终在晶界面取向织构和材料结构稳定性之间构建了有益关联。做为体视学技术和轻合金结构之间的学科交叉,本研究发展了空间意义上晶界面的划分技术和取向差角校正计算技术,实现了晶界面结构对材料组织结构性能的有效反馈,并可形成对同类型研究的参考和借鉴。

The stability of fusion welding structures of light alloy joints is significant to the aeronautic and astronautic fields.In this paper,the research subject is investigated from the perspective of grain boundary structures.The fusion welding zone of a 5 series aluminium alloy was taken as the example,and the scanning electron microscopy,electron backscatter diffraction(EBSD),and statistical grain boundary structure analysis methods were utilized.First,the heat-affected zone(HAZ),equiaxed zone(EQZ),and fusion zone(FZ)were spatially separated.Then,the corresponding misorientation angles across the grain boundary planes were calculated for each zone.Next,the orientation texture of habit planes was studied via five parameter analysis(FPA)method for the separated zones.Based on these work,the beneficial correlations between the orientation texture of habit planes and the structural stability of the material were established.With the combination of stereology and the structure of light alloys,the research develops the extraction and classification technology of grain boundaries in the spatial sense,and proposes the misorientation angle analysis method of grain boundary planes,which realizes a positive feedback of grain boundary structures to material properties,and can provide effective references for similar studies.