Decontamination Characteristics of 304 Stainless Steel Surfaces by a Q-switched Nd:YAG Laser at 532 nm

국문 초록 (Abstract)

레이저 용발법에 의한 금속 표면 제염특성을 평가하였다. 레이저로는 파장 532 nm, 펄스에너지 150 mJ, 펄스폭 5 ns의 큐스위치 Nd:YAG 를 적용하였고, 금속 표면에 CsNO3, Co(NH4)2(SO4)2, Eu2O3 그리고 CeO2를 오염시켜 이들의 제염 특성을 평가하였다. 제염 변수로는 레이저 적용횟수, 레이저 에너지 밀도 및 레이저 조사 각도 특성을 평가하였으며 각각 8, 13.3 J/cm2 및 30o의 최적 조건을 확인하였다. 제염 효율은 오염성분의 비점과 관련이 있었으며 CsNO3>Co(NH4)2(SO4)2>Eu2O3>CeO2 순이었다. 또한 여러 에너지 밀도 조건에서 스테인레스 스틸 재질의 식각 깊이 제어 특성을 규명하였다.

다국어 초록 (Multilingual Abstract)

Metal surface decontamination characteristics were investigated by using a laser ablation method. A second harmonic generation of a Q-switched Nd:YAG laser with a wave length of 532 nm, a pulse energy of 150 mJ and a pulse width of 5 ns was employed to assess the decontamination performance for metal surfaces contaminated with CsNO3, Co(NH4)2(SO4)2, Eu2O3 and CeO2. The ablation behavior was investigated for the decontamination variables such as a number of laser shots, laser fluence and an irradiation angle. Their optimum values were found to be 8,13.3 J/cm2 and 30o, respectively. The decontamination efficiency was different depending on the kinds of the contaminated ions, due to their different melting and boiling points and was in the order: CsNO3>Co(NH4)2(SO4)2>Eu2O3>CeO2. We also evaluated a correlation between the metal ablation thickness and the number of laser shots for the different laser fluences.

목차 (Table of Contents)

• Abstract
• 요약
• I. Introduction
• II. Experimental
• 1. Specimen preparation and analysis
• 2. Laser Irradiation Setup
• III. Resykts abd Discussion
• 1. Characterization of Samples
• 2. Effect if laser fluence
• 3. Effect if tge bynber if kaser shots
• 4. Surface temperature evaluation
• 5. Effect of lasser irradiation angle
• 6. Correlation of the ablation depth and the number of laser shots
• IV. Conclusion
• Reference