本研究期藉由非破壞檢測之渦電流方式來探討應用於航太零件之特殊中高週波及滲碳熱處理金屬棒材之硬化深度。棒形之合金素材應用於航太零組件方面非常廣泛，如主要傳動機構及飛行操縱面之致動器等。對應用於旋轉及傳動機構之航太零組件而言，其主要之要求為保持工件表面之強度卻同時需顧及其內部之韌性。為達成以上的需求，最主要的熱處理方式即為電磁感應傳導之中高週波硬化方式(Medium and high frequency induction hardening and tempering)或滲碳(Carburizing)和滲氮(Nitriding)等方式，以使物件表面之硬化程度和深度符合一般航太標準規範。而目前依前述方式之熱處理後之工件，大部分均以破壞方式以檢測其硬度與深度，如工件切片後再以硬度試驗機來量測，此種方式不僅消耗大量材料且必須花費大量工時而無法得到即時資訊。而本論文主要是以非破壞檢測之渦電流方式量測其值。本研究主要利用物件經熱處理後，碳原子滲入工件之表面，而造成物件之機械性質改變之外，其導電特性亦隨之改變，所以可利用物件之導電率變化，量測熱處理前後工件硬度及硬化深度之變化，進而控制航太精密零件特殊熱處理之製程。 This research is concerned with the experimental investigations of thedepth of hardening of circular shaft after medium and high frequencyinduction heat treatment by using non-destructive methods. Therod-shaped steel has been widely used in aerospace industry; e.g.,turbine's transmission shaft and leading edge flap actuator. For thesteel rod that have the mentioned purposes, their outer surfaces haveto keep certain strength or hardiness but at the same time their coreshave to keep soft for maintaining the ductility. The main heattreatment method for certain special high strength alloy to conformthe specifications is medium or high frequency hardening orcarburizing and nitriding. In general, the steel rod has to be cut toa slice in order to get the hardening information after certain heattreatment processes. It is a time consuming processes and will cost alot of materials and will not have an immediate result. It has torepeat the whole processes if the results do not conform to thestandard. Therefore, a main object of this work is to use the eddycurrent method to measure the depth of hardening non-destructivelywhich will be more effectiveness and practicality. Nevertheless, allresults studied by this work can be an important data for aerospaceengineering used for process control.
