球墨鑄鐵有優異的機械性質，用於各工業領域上，而高矽球墨鑄鐵具耐高溫氧化能力，若添加鉬元素，則高溫時的強度可再提升。
本篇論文利用水冷激銅模促使高矽鉬球墨鑄鐵單向凝固，藉此觀察凝固過程中不同的冷卻速率下球狀石墨大小、元素偏析生成的共晶碳化物及微觀組織的變化。利用示差掃描熱量計分析鑄件各位置的熱量反應，並與冷卻速率曲線比較探討。使用電解腐蝕技術將肥粒鐵基地溶解掉，使共晶碳化物M6C突出並以SEM觀察立體形態以探討成長模式。
結果發現，鑄件的冷卻速度快或是慢，魚骨狀共晶碳化物M6C皆在晶界處形成，魚骨狀碳化物外圍還有顆粒狀碳化物;魚骨狀碳化物成長模式，是從已凝固的沃斯田鐵晶粒間相接處開始晶出，而最後的凝固液體會因冷卻速度不同成長不同形態魚骨狀碳化物; DSC分析中高矽鉬球墨鑄鐵在升溫及降溫過程中的潛熱平均值與文獻是相當的。

Ductile iron, with superior mechanical properties, has been applied in various industrial fields; high silicon ductile iron has a good resistance to high temperature oxidation, but with the adding of molybdenum elements will result in the increasing of high temperature strength.
In this paper, using a water-cooled copper mold to achieve unidirectional solidification of high silicon molybdenum ductile iron castings, quality of spheroidal graphite and microstructure of eutectic carbides are presented. Thermal analysis of the casting by using Differential Scanning Calorimetry (DSC) analysis was conducted to calculate value of latent heat of this grade of ductile iron. Electrolytic deep etching technique was used to study the stereo structure of fish-bone M6C structure in the eutectic carbide.
The Results shows regardless of the cooling rate is high or low, fish bone-like eutectic carbides appears between grain boundaries, at that vicinity which precipitates with tiny granular carbide; several stereo morphologies of this eutectic carbides were studied and based on that a growth model is proposed in this thesis; DSC analysis of high silicon molybdenum ductile iron in the heating and cooling process latent heat average value with the literature is equivalent.

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