| Title |
Research Paper - Transformations - : Effect of PFC Parameters on the Thickness and Surface Defect of Amorphous Alloy Ribbon |
| Authors |
문성환(Sung Hwan Moon); 이기선(Kee Sun Lee); 오규환(Kyu Hwan Oh); 나형용(Hyung Yong Ra); 송용설(Yong Sul Song); 김문철(Moon Chul Kim) |
| Abstract |
Co_(68)Fe₄Cr₄B_(11)Si_(13) amorphous ribbon was fabricated by PFC(Planar Flow Casting) process. The effect of PFC parameters on the thickness and surface defects of amorphous ribbon was examined. The thickness of amorphous ribbon is proportional to the square root of melt ejection pressure and nozzle to roll distance, gap, but inversely proportional to the wheel speed and melt temperature. Gap is closely related with the increase of internal pressure in melt puddle. Surface defects of amorphous ribbon are classified into droplet, oxide film, air pocket and wave pattern. These surface defects result from entrapped air in puddle, poor wettability between liquid metal and cooling wheel, and instability of melt puddle. The increase of ejection pressure or decrease of gap size reduced surface defects, because increase of puddle internal pressure makes melt puddle more stable. Decreasing of gap size was the most effective method to reduce thickness and improve surface quality of amorphous ribbon. |