Heterostructure high-entropy alloys with exceptional thermal stability and resistance towards intermediate temperature embrittlement

•The heterogeneous columnar-grained structure demonstrated exceptional thermal stability even with high deformation energy stored in the large-size columnar-grained region. The precipitation of the intermetallic phase consumes the deformation energy and reduces the driving force for recrystallization on the one hand; on the other hand, the high-density precipitation effectively impedes dislocation rearrangement and exerts a pinning effect on grain boundaries.•A quantitative viewpoint into the competing kinetic factors governing the thermal stability of the heterogeneous columnar-grained structure is also given, that is, the driving force for recrystallization provided by the restored deformation energy and the Zener pinning pressure induced by high-density precipitates.•The heterostructure demonstrated exceptional resistance towards intermediate temperature embrittlement.