指導教授:吳錫侃臺灣大學:材料科學與工程學研究所李宗縉Lee, Tsung-ChingTsung-ChingLee2014-11-262018-06-282014-11-262018-06-282014http://ntur.lib.ntu.edu.tw//handle/246246/262048本文研究四種不同成分之富鈦及富鎳鈦鎳矽三元形狀記憶合金(SMAs)的析出物、變態行為及顯微組織等,並探討經過時效、熱循環及冷加工退火後之變態溫度的變化。Si之添加傾向替代Ni的原子位置,但其固溶性不佳,故在固溶處理後就有許多的第二相析出,富鎳鈦鎳矽SMAs之析出物為Ti5Ni4Si及Ti2Ni3Si,富鈦鈦鎳矽SMA中則有Ti2Ni及Ti5Si3。固溶處理後各鈦鎳矽SMAs均為B2↔B19’ 麻田散體變態,由EPMA及DSC結果可知,其變態溫度與基地成分之Ti/(Si+Ni) 比值有關,變態時之最大阻尼值可達0.098到0.162之間,皆為良好的制震材料。經熱循環100次導致變態溫度下降約10~20℃,唯仍維持B2↔B19’相變態,未有R相變態之產生。富鎳Ti48Ni50Si2 SMA經時效後,因Ti3Ni4在晶界及晶粒內部析出速率的不同,在300℃×72hr時效者出現B2→R(晶界附近)、B2→B19’(晶粒內部) 及R→B19’(晶界附近)的三階相變態;在400℃×120hr時效者在晶界附近和晶粒內部分別產生兩階之B2→R→B19’而有四階的相變態;而在650℃時效者,因析出物尺寸較大且有穩定態之TiNi3的析出,故成為一階的B2↔B19’相變態。Ti48Ni50Si2 SMA經時效處理後,Ti3Ni4析出物的大小及分布將影響到析出硬化的效果,其中經300℃×24hr時效者可達最大硬度422Hv,同時形狀回復率也提升至96.5%。經20%冷加工的Ti49Ni50Si1 SMA及40%冷加工的Ti49.5Ni50Si0.5 SMA在特定的時效溫度下,會有R相變態的產生,而使降溫時成為B2→R→B19’之二階相變態,此因析出物的整合應力場與冷加工後的殘留應力所共同造成的。In this study, four kinds of Ti-rich and Ni-rich TiNiSi ternary shape memory alloys (SMAs) are investigated for their precipitates, transformation behavior and microstructure. The effects of aging, thermal cycling and cold working on their transformation temperatures are also studied. The Si added in TiNi SMAs has a tendency to substitute for the Ni. But the solubility of Si in the TiNi matrix is low, which gives a significant TiNi-silicides precipitation. Four different TiNi-silicides are observed, in which Ti5Ni4Si and Ti2Ni3Si are formed in three Ni-rich TiNiSi SMAs, while Ti2Ni and Ti5Si3 are found in a Ti-rich TiNiSi SMA. The TiNiSi SMAs exhibit a B2↔B19’ transformation after solution treatment, and their transformation temperatures are related to the Ti/(Si+Ni) ratio in the matrix. The tanδ values of TiNiSi SMAs reach 0.098~0.162, which indicate that these SMAs exhibit excellent damping performance. Transformation temperatures of TiNiSi SMAs decrease 10~20℃ after 100 thermal cycling, but they still remain B2↔B19’. Due to different precipitation rates occurred at the grain boundaries and inside the grains, the Ni-rich Ti48Ni50Si2 SMA behaves a multi-stage transformation after 300~550℃ aging. Furthermore, the precipitation hardening of Ti48Ni50Si2 SMA depends on the size and distribution of Ti3Ni4 precipitates, and the maximum hardness of 422Hv is found after the SMA is aged at 300℃×24hr, in which the recovery can reach 96.5%. Under 350~650℃ aging temperature, the DSC results show the appearance of the R phase peak in 20% and 40% cold-rolled Ti49Ni50Si1 and Ti49.5Ni50Si0.5 SMAs, respectively, due to the coherent strain around precipitations and the existing residual strain after cold working.致謝 iii 摘要 v Abstract vii 目錄 ix 第一章 前言 1 第二章 文獻回顧 3 2-1 形狀記憶合金簡介 3 2-2 形狀記憶合金之特性 4 2-2-1 熱彈性麻田散體變態 4 2-2-2 形狀記憶效應 6 2-2-3 超彈性 7 2-3 TiNi形狀記憶合金 9 2-4 富鎳TiNi形狀記憶合金之時效處理效應 10 2-5 富鎳TiNi形狀記憶合金之多階相變態行為 12 2-6 鈦鎳矽形狀記憶合金 15 2-7 鈦鎳形狀記憶合金的制振能特性 17 第三章 實驗方法及步驟 37 3-1 鈦鎳矽三元形狀記憶合金試片準備 37 3-2 EPMA成分分析 38 3-3 OM與SEM觀察 38 3-4 DSC熱分析儀變態點量測 38 3-5 熱循環試驗 39 3-6 動態機械分析儀DMA量測 40 3-7 應變回復率測試 40 3-8 微硬度測試 41 3-9 XRD晶體結構分析 41 3-10 時效處理 41 3-11 冷輥壓 42 第四章 結果與討論 51 4-1 鈦鎳矽形狀記憶合金性質之量測 51 4-1-1 固溶處理後EPMA觀察結果與討論 51 4-1-2 固溶處理後OM及 SEM金相觀察結果 53 4-1-3 DSC變態點測量結果 54 4-1-4 熱循環對鈦鎳矽形狀記憶合金相變態行為之影響 56 4-1-5 DMA測量結果與討論 57 4-1-6 形狀回復率之測試結果 59 4-1-7 硬度測試結果 59 4-1-8 XRD之測試結果 60 4-1-9 400℃時效後之DSC結果 60 4-2 時效對Ti48Ni50Si2形狀記憶合金變態之影響 61 4-2-1 Ti48Ni50Si2合金250℃及300℃時效後之DSC測試結果 62 4-2-2 Ti48Ni50Si2合金350℃時效後之DSC測試結果 65 4-2-3 Ti48Ni50Si2合金400℃時效後之DSC測試結果 66 4-2-4 Ti48Ni50Si2合金550℃及650℃時效後之DSC測試結果 69 4-3 時效後Ti48Ni50Si2形狀記憶合金之硬度測試結果 70 4-3-1 Ti48Ni50Si2合金250℃時效後之硬度測試結果 70 4-3-2 Ti48Ni50Si2合金300℃時效後之硬度測試結果 71 4-3-3 Ti48Ni50Si2合金350℃時效後之硬度測試結果 71 4-3-4 Ti48Ni50Si2合金400℃時效後之硬度測試結果 72 4-3-5 Ti48Ni50Si2合金550℃時效後之硬度測試結果 72 4-3-6 Ti48Ni50Si2合金650℃時效後之硬度測試結果 72 4-3-7 Ti48Ni50Si2合金時效後DSC與硬度結果之討論 73 4-4 退火對軋延後Ti49Ni50Si1形狀記憶合金變態及性質之影響 75 4-4-1 DSC變態點測試結果 76 4-4-2 冷加工後Ti49Ni50Si1 合金均質性之討論 78 4-4-3 DMA變態點測試結果 79 4-5 退火對軋延後Ti49.5Ni50Si0.5形狀記憶合金變態及性質之影響 81 4-6 Ti51Ni48Si1形狀記憶合金析出現象之研究 82 第五章 結論 143 參考文獻 14620826689 bytesapplication/pdf論文公開時間:2019/07/29論文使用權限:同意有償授權(權利金給回饋學校)鈦鎳矽形狀記憶合金多階相變態Ti3Ni4析出物時效處理制震能鈦鎳矽三元形狀記憶合金之研究Studies on TiNiSi Ternary Shape Memory Alloysthesishttp://ntur.lib.ntu.edu.tw/bitstream/246246/262048/1/ntu-103-R01527006-1.pdf