鉬的許多優異性質使鉬能廣泛地運用在許多半導體及製造工業上，而鉬之高熔點(2620℃)，使得鉬多以粉末冶金方法製造，然而由於燒結溫度仍需相當高(約1700℃~2200℃)，且燒結的製程因素，包括粉末純度、時間和氣氛等對燒結後性質亦影響甚大，因此一直以來鉬的燒結研究成為製造鉬的最主要課題。前人研究曾指出微量的鎳可使鉬之燒結溫度降低，於1300℃即可迅速燒結緻密化，此方法一般稱為活化燒結(Activated Sintering)，但此方法唯一的缺點為鉬會變脆。
本研究的目的即在對鉬的燒結進行研究：實驗中以1750℃、0.08torr的真空度進行高溫真空燒結，探討燒結時間及氣氛對鉬燒結性質的影響；另在鉬中加入不同含量的鎳分別在1300℃和1370℃進行活化燒結及液相燒結以了解整個活化燒結機構並找出燒結體變脆的主因。
實驗結果顯示：真空燒結時間對鉬燒結密度影響不大，但會對晶粒尺寸和延性造成影響，燒結5小時的試片晶粒雖小但沒有任何的延性，10小時後晶粒變大卻具有很好的延性，造成此現象的原因為燒結後鉬中的氧含量不同所致。
而經由微量鎳的添加，鉬可在1300℃作活化燒結和1370℃作液相燒結並迅速達到緻密化，但不論活化燒結或液相燒結，鉬均會變得非常脆，造成鉬變脆的原因經由實驗的結果與討論認為鉬粒與鉬粒間形成了MoNi介金屬相，而MoNi為又硬又脆的材料，因而成為活化燒結及液相燒結後鉬變脆的主因。
此外，實驗中亦發現活化燒結所添加1.5wt%鎳的含量中，若以銅取代三分之一的鎳形成Mo-1wt%Ni-0.5wt%Cu時，其燒結效果比Mo-1.5wt%Ni的活化燒結及液相燒結效果更顯著，燒結密度可達到99%。

The sintering temperature of molybdenum is usually greater than 1700℃. Although it has been postulated that lower sintering temperature can be achieved through the activated sintering technique by adding a small quantity of nickel, palladium or cobalt, the brittleness of such sintered molybdenum has prevent it from being accepted by the industry. The purpose of this study was to find out the cause of the brittleness of activated sintered molybdenum.
In the experiment, pure molybdenum powders were compacted and then sintered at 1750℃ in vacuum in order to evaluate the effect of sintering time and atmosphere on the post-sintered properties. After selecting the adequate parameters, molybdenum compacts with different contents of nickel powder additives were sintered at 1300℃ (activated sintering) and 1370℃ (liquid phase sintering), respectively, in order to understand the mechanism of enhanced sintering and to find out the causes of brittleness.
The results showed that, for vacuum sintering, 5-hour sintering gave fine grain size but with poor ductility compared to those with 10-hour sintering. The phenomenon was caused by different oxygen contents in the sintered compacts, which decreased as the sintering time increased.
For activated sintering and liquid phase sintering, it was found that a layer MoNi existed in the grain boundaries of sintered compacts. This intermetallic compound is hard and brittle and leads to the brittle behavior of the sintered compact.
It was also found that when 33.3% of Ni was replaced by Cu, Mo-1%Ni-0.5%Cu for example, the relative sintered density increased from 95.3% to 99% for activated sintering.

摘要……………………………………………………………………….i
Abstract………………………………………………………………….iii
目錄………………………………………………………………………v
表目錄………………………………………………………………….viii
圖目錄…………………………………………………………………...ix
第一章、 簡介
1-1 鉬的特性與用途1
1-2 鉬的粉末冶金製程2
1-2-1 純鉬粉的製造2
1-2-2 鉬粉的成形與燒結3
1-2-3 碳氮氧對鉬延性-脆性轉換溫度的影響4
1-2-4 燒結後的加工4
1-3 活化燒結4
1-3-1 活化燒結的機構5
1-3-2 活化劑的選擇6
1-3-3 活化燒結的瓶頸-燒結體的脆化7
1-3-4 脆化的成因7
1-3-5 有關改善活化燒結後脆性的研究9
1-4 研究目的11
第二章、實驗
2-1 實驗流程與實驗設計28
2-2 粉末特性分析28
2-2-1 鉬粉28
2-2-2 鉬粉29
2-2-3 銅粉29
2-3 混合29
2-4 成形29
2-5 燒結30
2-6 燒結體密度測量30
2-7 機械性質測試30
2-7-1 延性測試30
2-7-2 硬度31
2-8 破斷面形態觀察31
2-9 金相製備31
2-10 晶粒尺寸量測32
2-11 成份分析32
2-12 結構分析33
2-13 實驗儀器33
第三章、結果與討論
3-1 純鉬粉之真空燒結45
3-1-1 不同燒結時間之燒結密度45
3-1-2 不同燒結時間之晶粒尺寸45
3-1-3 不同燒結時間之硬度45
3-1-4 不同燒結時間之抗折強度(延性測試)46
3-1-5 不同燒結時間之微觀組織46
3-1-6 不同燒結時間之碳、氮、氧含量及成份分析46
3-1-7 不同燒結時間之X光繞射分析47
3-1-8 生胚先經過還原處理後之真空燒結48
3-1-9 真空燒結時間對鉬燒結性質之影響48
3-1-10 燒結過程中二氧化鉬的消失49
3-1-11 二氧化鉬的分解50
3-2 鉬的活化燒結及液相燒結51
3-2-1 燒結密度52
3-2-2 抗折強度(延性測試)52
3-2-3 微觀組織53
3-2-4 硬度54
3-2-5 碳、氮、氧含量分析54
3-2-6 EPMA成份分析54
3-2-7 破斷面表面成份分析55
3-2-8 X光繞射分析56
3-2-9 活化燒結與液相燒結對燒結緻密化的影響57
3-2-10 活化燒結機構的探討57
3-2-11 活化燒結與液相燒結後脆化成因的探討58
3-3 鉬-鎳-銅三元系統的燒結59
3-3-1 燒結密度59
3-3-2 Mo-1%Ni-0.5%Cu的燒結後性質60
3-3-3 微觀組織及成份、結構分析61
3-3-4 添加銅的燒結效果61
第四章 結論97
第五章 未來工作98
參考文獻99

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