本論文的主題為研究高分子材料在進行奈米壓痕試驗時所表現
出來的時依(Time-dependent)行為。透過以二次Kekvin模型為基礎，加上實驗所觀察到各負載條件下，壓深對時間的關係來建立模型，且透過模型中壓深理論解，可把每一段負載條件下的壓深對時間關係清楚表示出來。當各元件的參數給予正確時，本模型可將實驗結果擬合的相當接近。
在高分子材料中，PMMA與PU分別代表彈性恢復量(Elastic
recovery)較小與較大的材料，透過本研究所建立之模型，可將此兩種高分子材料在壓痕試驗中的潛變(Creep)變形與相位落後(Phase lag)的行為清楚地描述出來。在定負載下，可觀察到試件的潛變變形，為反應前段負載條件的遲滯行為；與黏彈性質所造成材料壓深與時間呈線性關係的行為。在震盪加載之下，壓深與負載會有相位落後的情形，在透過不同的震盪條件下，可發現相位落後與震盪頻率成一線性正比關係。
在利用原子力顯微鏡(Atomic force microscope, AFM)掃描壓痕實驗後試件的殘餘形貌(Residual profile)，可應證高分子材料為幾何密合(Accommodation)的可靠假設。且針對本模型提出一個估算機械性質的方法，可不必透過面積函數(Area function)便可得到楊氏模數(Young’s modulus)與硬度(Hardness)。並且針對高分子這類黏彈性質較大的材料，在停滯段部份所發生無法定負載與負載衰退的行為進行討論。

　　The topical subject in this study is to investigate the polymer’s time-dependent behaviors. Through the arrangements of the applied load for nanoindentation tests, the experimental results of polymers varying with time arising in the loading, unloading, dwelling, and oscillating load processes are obtained. These indentation responses offer the help to establish the mechanical model for the load-depth behavior in polymers. Based on this model, the depth solutions are solved for these applied load conditions. The PMMA and PU materials are adopted as the typical examples with a low and a high recovery respectively in polymers. The experimental results of these two materials are fitted well if the coefficients used in this model are properly given. The phase lag exhibited between the responding depth and the oscillating load is investigated to be linear proportional to frequency. The residual cavity profile of the PMMA scanned by an atomic force microscope gives the validity of accommodation assumption. The effect of the overshooting occurring in the dwelling process is also discussed.

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