本研究目的為藉由觀察微結構及機械性質探討銅鋅合金通電後造成性質變化的機制，將銅鋅合金薄帶施加10000-16000 A/cm2之電流密度通電2h-5cycles後，利用液態氮急速冷卻試片以觀察通電處理後之微結構。實驗結果顯示隨電流密度的增加，試片之片電阻及微硬度增加比例持續上升，並藉由阿瑞尼斯方程式計算微硬度變化的活化能，顯示活化能可分為低電流密度(10000-13000 A/cm2)之23.9 kJ/mol以及高電流密度(13000-16000 A/cm2)之3.6 kJ/mol。電子背向散射繞射分析(EBSD)在低電流密度區段的試片中觀察到細小晶粒佔比增加、雙晶比例增加等再結晶行為所伴隨之現象，並透過HRTEM在通電試片中觀察到差排的生成。推測電子風力使原子移動而產生差排，新生成的差排作為成核點，伴隨電流生成的焦耳熱效應促進材料發生非完整再結晶行為，因此晶界效應(Grain boundary effet)在本研究中會影響性質表現，但由於平均晶粒尺寸變化並不明顯，仍以應變場效應(Strain field effect)作為低電流密度區段性質變化之主要機制；透過HRTEM在高電流密度的試片中觀察到差排密度急遽上升至1017 m-2以上，推測高電流密度引起之電子風力嚴重破壞晶格結構，以應變場效應作為高電流密度區段性質變化之主要機制。

This study discussed the mechanism of properties change on Cu36Zn alloy after current stressing through the investigation of microstructure and mechanical properties. The strip specimens were subjected to 10000~16000 A/cm2 D.C. for 2h-5cycles and then were rapidly quenched with liquid nitrogen after current stressing to freeze the microstructure for investigation. The results show that the extent of variation of sheet resistance and micro-hardness kept increasing with the increase of current density. The activation energies of micro-hardness change, calculated via Arrhenius equation, were 23.9kJ/mol for low current density (10000~13000 A/cm2) and 3.6kJ/mol for high current density (13000~16000 A/cm2). EBSD analysis indicated that the recrystallization was accompanied by an increase of small grain fraction and twin fraction when the specimen was stressed under low current density. The uncompleted recrystallization behavior is likely ascribed to generation of dislocation induced by electron wind force. The newly formed dislocations act as the nucleation sites for recrystallization. The current-induced Joule heat facilitates the recrystallization behavior. Grain boundary effect will affect the properties, but the change of grain size is not obvious. So strain field effect is still the main mechanism of properties change under low current density. HRTEM analysis indicated that more dislocations were produced in the specimen at high current density, the dislocation density increased abruptly up to 1017 m-2. The properties change under hugh current density is ascribed to strain field effect.

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