在正常工作的条件下,部分医用X射线管中的纯钨靶表面会逐渐变得粗糙,在粗糙区进一步会出现表面裂纹,但同型号的进口钨靶表面却几乎没有粗糙区和裂纹出现。采用SEM、EDS和化学成分测试等方法,对两种钨靶进行了研究和比较。结果显示,杂质元素的含量偏高和沿晶界的偏析以及不均匀的钨晶粒是造成国产钨靶表面损伤的主要原因。 Under normal working conditions, the surface of pure tungsten in some medical X-ray tubes will gradually become rough, and surface cracks will appear in the rough area. However, there are almost no rough areas and cracks on the surface of imported tungsten target of the same type. Using the methods of SEM, EDS and chemical composition testing, the two tungsten targets were studied and compared. The results show that the high content of impurity elements and the segregation along the grain boundaries as well as the non-uniform tungsten grains are the main causes of the domestic tungsten target surface damage.