林招松2006-07-252018-06-282006-07-252018-06-282003http://ntur.lib.ntu.edu.tw//handle/246246/12448本計畫探討電鍍液組成和操作參數對鍍層磷含量、硬度、內應力和電流效率的影響，藉以發展適合高溫用微電鑄體的製程。實驗結果顯示直流電鍍時，亞磷酸的添加會使柱狀晶組織逐漸轉變為層狀的組織，鍍層晶粒由粗大柱狀晶細化為奈米級晶粒，同時大幅提高鍍層硬度，然而電流效率卻下降，而脈衝電鍍則可大幅提 昇電流效率。經由TEM 照片觀察，亞磷酸的添加在高磷含量的部分可以觀察到奈米級的晶粒。含磷合金在低於400℃熱處理1 小時後，硬度因含磷介金屬化合物的析出而增加，熱處理溫度超過500℃ 時，鎳基材的再結晶與晶粒成長導致鍍層硬度下降。同時，鍍層磷含量升高會降低鍍層再結晶溫度，但會有較多介金屬化合物的析出，阻礙晶粒成長而保有較高的高溫強度。另外，鈷磷合金的抗高溫軟化能力優於鎳磷合金。The effects of electrolyte composition and electroplating parameters on the phosphorus content, deposit hardness, internal stress and cathodic current efficiency for Ni-P and Co-P electrodeposits were investigated so as to develop a process for micro-electroforming the mechanic elements for high-temperature applications. Experimental results indicate that with increasing the bath phosphorous acid concentration, the grain structure of the Ni-P and Co-P alloys, plated at a current density of 8 A/dm2, was refined as compared to the coarse columnar structure associated with pure Ni and Co coatings, and hence their hardness was markedly increased, whereas the cathodic current efficiency monotonously decreased with the phosphorus acid concentration. Conversely, the efficiency was enhanced by means of pulse current. TEM further revealed the coatings plated from the bath with 40 g l-1 phosphorus acid consisted of nano grains. When annealed at temperatures less than 400 ℃, the hardness of the alloy coatings increased due to the precipitation of P-bearing intermetallic compounds. However, the hardness of the alloy coatings dropped after 1 h of annealing at temperatures exceeding 500 ℃ because of the recrystallization and grain growth of the nickel matrix. Finally, the Co-P alloys had larger high-temperature strength than the Ni-P alloys.application/pdf546105 bytesapplication/pdfzh-TW國立臺灣大學材料科學與工程學研究所胺基磺酸浴電鍍鎳磷合金電鍍鈷磷合金奈米晶粒Nickel sulfamate bathNi-P electrodepositCo-P electrodepositnano grainreporthttp://ntur.lib.ntu.edu.tw/bitstream/246246/12448/1/912216E002040.pdf