There are many factors effecting on the formation of the blowholes, such as substrate surface state, alloy powder system, crystalline growth velocity, etc.
气孔形成与多方面因素有关,包括基体表面状态、冶金材料体系和结晶速度等。
3
The result showed that the crack forming was due to the billet metal in the subcutaneous blowholes were oxidated during heating process and could not be sticked.