Effect of specimen temperature on crystallization during laser remeltitng Zr₅₅Cu₃₀Al₁₀Ni₅ bulk metallic glass

Zr₅₅Cu₃₀Al₁₀Ni₅ bulk metallic glasses were remelted by pulsed laser at liquid N (Ar) cooling, room temperature and 473 K. The results show that the effect of specimen temperatures on the crystallization of specimens during laser remelting metallic glasses depends on the Ar blowing. If there is no Ar blowing, the crystallization of the specimen during laser remelting under liquid Ar cooling and room temperature is similar while the molten pool is deeper for liquid Ar cooling. And the specimen remelted at 473 K was most seriously crystallized with the deepest molten pool. But comparing the specimen at room temperature, the crystallization of the specimen at liquid N was suppressed during laser remelting with Ar blowing. The effects of specimen temperatures on the crystallization of metallic glasses during laser remelting are: First, the lower specimen temperature can increase the cooling rate of specimen and therefore reduce its crystallization. Secondly, the lower specimen temperature makes the atmosphere around the specimen cooled down, reduces the shielding effect of plasma and increases the actual laser energy input into the specimen, resulting in more serious crystallization of the specimen. If there is Ar blowing, the atmosphere temperatures are similar to that at the liquid Ar cooling leading to the crystallization of the specimen to reduced. If there is no Ar blowing, the atmosphere temperature is similar to the temperature of specimen itself. In this case, the crystallization of the specimens is jointly determined by the temperature of the specimen itself and the atmosphere temperature around the specimens, which is not monotonous.