HWAHAK KONGHAK, Vol.41, No.1, 58-63, February, 2003
금속분말사출물에서 이성분 혼합 초임계유체를 이용한 바인더 제거
Binary Supercritical Fluid Mixture Debinding in Metal Injection Molded Part
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초록
최근 들어, 급속사출성형공정에서 주결합제로 많이 사용되는 paraffin wax를 제거하기 위한 용매로 초임계 CO2에 대한 연구가 활발히 진행되고 있다. 본 연구에서는 비극성 유기물질에 강한 용해력을 보이는 propane의 특성을 이용하기 위해서 CO2와 propane의 혼합유체를 용매로 선택하였고, 초임계 조건에서 탈지실험을 수행하였다. 탈지 실험은 온도 348.15 K, 압력 15 MPa-25 MPa의 조건에서 propane의 함량을 변화시키면서 수행하였고, 시간에 따른 탈지율을 비교하였다. 또한 탈지속도를 Fick의 diffusion model에 적용시켜 계산하였으며, 이를 실험치와 비교해 본 결과 잘 일치하는 것을 확인하였고, 이를 이용하여 paraffin wax의 확산도를 구하였다.
In recent years, the study of supercritical CO2 that can be used as solvent which extracts paraffin wax in metal injection molding process is going on. In this work, we used binary mixture of CO2 and propane in supercritical conditions in order to use a special property of propane that has strong solubility for nonpolar organic material. Debinding experiments were performed by varying weight ratio of propane at constant temperature(348.15 K) and various pressure (15-25 MPa). The binder removal rates at each condition were compared. Moreover, kinetics of debinding was studied by applying the Fick's diffusion model. The calculated debinding rate showed good agreement with experimental data. By using this model, we could evaluate diffusivity of paraffin wax.
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