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。
The results show that high content of impurity elements, segregation along grain boundaries and uneven grain size are main reasons for the surface damage of domestic tungsten targets.
SEM对试样微观形貌的研究表明，晶粒大小不均匀是这种材料的微观特征。
Research of SEM indicates that the heterogeneity of grain size is the typical microstructure of the materials.
随着保温时间的增加，异常晶粒长大所造成的晶粒不均匀程度逐渐降低。
With the increase of holding time during heating, grains tend to be uniform.
应用推荐