純鎳由於其優秀的耐腐蝕性，被廣泛應用於工業領域如化工運輸中的管道和法蘭的製造。然而，在製造這些工業組件的過程中，需要反覆進行退火處理，這也導致了使用傳統熱處理會有能耗高的隱患。新穎的電退火處理(Electrical annealing treatment)因其節能和高效的特性，被認為是傳統熱處理的一種潛在的替代方案，得以進一步有效控制材料的微結構和性質。本研究中對純鎳在電流引起的物理冶金行為進行了全面的研究，提供了對所產生的微結構和性質變化的詳細分析和討論，並與熱對照組實驗進行了比較。純鎳的電退火處理引起的性質變化通將透過微硬度和電阻率兩方面進行探討，分別使用微小維氏硬度計和四點探針儀進行測量。本研究使用電子背向散射繞射技術(Electron backscatter diffraction, EBSD)探討冷軋狀態和電處理純鎳條帶的微結構和織構變化。隨著電流密度的增加，電處理在超過臨界電流密度3.2 × 104 A/cm2通電1小時時誘發了嚴重的晶粒成長，晶粒成長被認為是導致顯著的微硬度降低(35.2%)和電阻率降低(11.4%)的主要原因。此外，電處理誘導了Σ3 60°<111>面心立方(Face-centered cubic, FCC)退火雙晶邊界比例的增加，進一步新穎電退火處理下晶界演變的機制也在這部分進行討論。局部方位差異(Kernel average misorientation, KAM)分析和幾何必要差排(Geometrically necessary dislocation, GND)密度的計算進一步支持了純鎳條帶電退火行為降低晶粒取向差異的現象。根據φ_2=0°,45°,65°的取向分佈函數(Orientation distribution function, ODF)圖可以發現由於晶粒成長，{001}<100>立方織構(Cube texture)比例增加。本研究還進行了一個熱對照組實驗以研究電流輔助處理的非熱效應貢獻。非熱效應的說明顯示它是導致微結構變化並引起性質改變的主要因素。與傳統熱處理相比，電退火處理提供了一個新的選擇，能夠通過改變處理過程的參數來控制材料性質，包括提高機械強度、增強導電性和通過細化微結構來改善性能。

Due to its excellent corrosion resistance, pure Ni is widely applied in various applications of the industry, for example, chemical shipping as the pipes or the flanges. However, repetitive annealing processes are necessary for the manufacture of these industrial components, which give rise to the concerns of severe energy consumption of the conventional heat treatment. Innovative electrical annealing treatment has been regarded as one potential alternative to conventional heat treatment due to its energy-saving and high-efficiency characteristics, aiming to manipulate the material’s microstructure and properties. In this study, a comprehensive investigation of the physical metallurgy behavior induced by the electric current in the pure Ni strips was conducted, offering a detailed analysis and discussion of the microstructural and property changes. The results were compared to those with the thermal annealing benchmark experiments. The changes in properties induced by the electrical annealing treatment of pure Ni were examined in terms of micro-hardness and electrical resistivity by using a Vickers micro-hardness tester and a four-point probe, respectively. The microstructures and textures of the as-rolled benchmark and current-treated pure Ni strips were investigated using electron backscatter diffraction (EBSD). Electro-treatment with an increasing current density above a threshold current density of 3.20 × 104 A/cm2 induced severe grain growth. Grain growth was proposed to contribute to the significant micro-hardness reduction of up to 35.2% and the 11.4% reduction in electrical resistivity. Moreover, the electro-treatment induced an increase in Σ3 60°<111> face-centered cubic (FCC) annealing twin boundary fraction. The mechanism of the boundary evolution under the innovative electrical annealing treatment was further discussed. The kernel average misorientation (KAM) analysis and the calculation of the geometrically necessary dislocation (GND) density further supported the electrical annealing behavior of the pure Ni strips to lower intra-grain misorientation. Based on the orientation distribution function (ODF) maps with φ_2=0°,45°,65°, it can be found that the {001)<100> Cube texture fraction increased due to grain growth. A thermal annealing benchmark experiment was also conducted to investigate the contribution of the athermal effect of the current-assisted treatment. The illustration of the athermal effect showed that it was the predominant factor in the microstructure evolution, which leads to variations in properties. The electrical annealing treatment offers a new option compared to the conventional heat treatment to manipulate material properties by alternating the parameters of the treatment process.

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