incoherent grain boundary

例句：

1. 1. The grain boundaries are not continuous in the sample.
   样品中的晶界不连续。
2. 2. The incoherent grain boundary is a major cause of fatigue failure.
   不连续的晶界是疲劳失效的主要原因。
3. 3. The grain boundary plays a crucial role in determining the mechanical properties of the material.
   晶界在决定材料机械性能方面起着关键作用。