有機添加物對Ti-6Al-4V合金電解滲氫之影響評估

The Effect of Organic Additives on Electrolytic Hydrogenation of Ti-6Al-4V Alloy

Ti-6Al-4V合金可經電解滲氫、真空除氫以達表面晶粒細化，增加氫之吸入量可增加晶粒細化深度。本研究嘗試於硫酸溶液中加入硫代尿素（thiourea）及其衍生物（derivatives），在不同電流密度及時間下進行電解滲氫、經由X光繞射儀（XRD）及輝光放電光譜儀（GDS）之分析結果顯示，添加硫代尿素衍生物有較優於添加硫代尿素之滲氫效果。此結果除因添加物特性不同外，亦與鈦合金可形成氫化物之特性有關。

Grain refinement of Ti-6Al-4V alloy can be achieved by eletrolytic hydrogenation and subsequent vacuum annealing. The depth of grain refinement increases with increasing hydrogen uptake. Cathodic charging was performed at various current densities and periods in 1N H2SO4(aq) with or without adding thiourea and its derivatives. The results analyzed by using X-ray diffractometry (XRD) and glow discharge spectrometry (GDS) show that hydrogenation performance is lower for the specimens charged with the addition of thiourea. This may partly arise from the properties of the additives and partly from those of hydrides fromed at the specimens surface during cathodic charging.