晶粒尺寸效應對銅奈米機械性質與變形機制影響之研究

Grain Size Effect on Nanomechanical Properties and Deformation Behavior of Copper

張守一(S. Y. Chang) ； 張庭魁(T. K. Chang) ； 蕭翔隆(H. L. Hsiao)

《材料科學與工程》 38卷3期 (2006/09) Pp. 162-168

https://doi.org/10.6409/JMSE.200609.0162

摘要

本研究利用奈米壓痕試驗探究不同晶粒尺寸銅試片之機械性質與變形行爲。實驗結果發現，塊材銅、濺鍍銅及電鍍銅等大晶粒尺寸試片，其硬度值隨晶粒尺寸減小而增加，由1.0 GPa增加至2.3 GPa，此結果遵循了”Hall-Petch”關係；在壓痕周圍可清楚地觀察到差排的存在，由此可判斷大晶粒尺寸銅試片之塑性變形是以差排的產生與滑移爲主。然而，以無電鍍法所沉積之銅膜晶粒尺寸約爲10 nm，其硬度卻下降至1.0 GPa；且在壓痕周圍觀察到晶界和三晶粒交接處有孔洞的產生，推測此孔洞是由於晶界滑移與晶粒旋轉所造成，因此使其硬度值下降。此外，晶粒尺寸越小之銅試片，由於晶界提供了一快速之擴散路徑，加上晶界滑移之效果，其潛變速率較大。

關鍵字

奈米壓痕測試 ； 機械性質 ； 差排滑移 ； 晶界滑移 ； 潛變

並列摘要

In this study, the mechanical properties and deformation behaviors of copper with different grain sizes have been investigated by nanoindentation. It was found that the hardness of copper with coarse grain sizes increased from 1.0 to 2.3 GPa as grain size decreased, following the Hall-Petch relation. Around indent marks, dislocations were clearly observed, indicating plastic deformation by dislocation formation and sliding. However, the hardness of electroless copper with a grain size of only 10 nm dropped to 1.0 GPa. Voids formed at grain boundaries and triple grain junctions due to grain boundary sliding and grain rotation, resulting in reduced hardness. Moreover, the creep strain rate of copper with a smaller grain size was lower due to the rapid diffusion path through grain boundaries and the effect of grain boundary sliding.

並列關鍵字

Nanoindentation ； Mechanical Properties ； Dislocation Sliding ； Grain-Boundary Sliding ； Creep