材料微结构-性能关系的"原位跟踪"观测技术与应用

在材料研究中"原位"测试技术占有非常重要的地位,它能将材料的组织形貌、化学成分和晶体结构等微结构与材料的性能和加工过程等一一地对应起来,从而获得更加真实反映材料组织与性能之间关系的试验结果。然而"原位"测试大多需要特殊并且昂贵的试验装置与设备,如电镜中配置的加热与拉伸样品台、环境扫描电镜等。实际上许多研究过程还很难进行"原位"观察。经过多年大量的实践,提出一种基于扫描电镜新的"原位跟踪"观察和测量技术。与传统的"原位"分析不同,在"原位跟踪"观测过程中,材料样品的处理过程是在扫描电镜外进行的。利用该技术研究了焊接熔合区的腐蚀和碳迁移过程,以及不锈钢材料在高温下的回复与再结晶。试验表明采用"原位跟踪"技术可获得与"原位"观测相同的效果。

"In-situ-tracking" technique and its application for material microstructure-property relationship evaluations

Playing a key role in materials researches,the "in-situ" analysis can establish a point to point relationship between the microstructure characteristics (including morphology,chemical composition and crystalline structure),and properties or processing.However,most of the "in-situ" experiments need special even expansive facilities,such as heating and tension sample holders in a scanning electron microscope (SEM),and environmental SEM.In practice,the "in-situ" approach is not suitable for many materials researches.This paper presents a novel "in-situ-tracking" technique based on the SEM.Different from the regular "in-situ" approach,the sample treatments are proceed outside the SEM during the "in-situ-tracking" analysis.By using this technique,the corrosion property and carbon migration at the fusion area of the dissimilar steel welded joints were studied,and the recovery and recrystallization process of the stainless steel during high temperature treatment.The experiment results show that the "in-situ-tracking" analysis can achieve the same effect as that of "in-situ" analysis.