黃銅為工業界常使用的工程材料，亦大量應用於電子通信產業中，為了加強加工性能及改善加工後的表面平整度，經常於黃銅中添加微量的鉛元素 (1-3 wt.%)，促使產生破碎的切削屑。然而，此舉會降低黃銅在高溫中的塑型性能，不僅造成不均勻變形，進而導致製程中斷料的危機，或是於其他加熱變形製程中破裂。故本研究將對熱擠型Cu38Zn3Pb合金的高溫機械性質做系統性的探討，並研究熱擠型Cu38Zn3Pb合金經過不同程度熱軋變形後的機械性質、切削性評估及抗脫鋅腐蝕能力。
實驗結果顯示，熱擠型Cu38Zn3Pb合金於500°C以上時有較高的拉伸延性，而衝擊韌性於中高溫區間有一個下降的區間存在，具有脆性效應，此溫度約在400 °C至600 °C間，直到700 °C以上時才恢復與衝擊韌性。破斷表徵與溫度關係為在低溫時是晶粒破裂，中溫時則呈現沿晶型的破壞行為，到了高溫範圍後又呈現穿晶破裂的形式。
熱擠型Cu38Zn3Pb合金於熱軋實驗中，經過熱軋後的Cu38Zn3Pb合金會發生明顯的動態再結晶現象，有助於組織的細化及機械性質的提升。此外，隨熱變形的程度上升，硬度隨之增加，並影響切削時產生的切屑形貌及大小。再者，由於熱變形時所造成的組織細化、晶界密度上升及差排堆積，將使得合金的腐蝕電流升高，耐蝕性能下降，較易受到脫鋅效應的影響。熱擠型Cu38Zn3Pb合金在400 °C至600 °C間具有中溫脆性，而高溫下延性與韌性均顯著提升，經切削加工評估可達連續切削條件之要求，相關熱作成果可提供銅業應用參考。

In order to enhance the processing performance and improve the surface flatness after cutting, a small amount of lead (1-3 wt.%) is often added to the brass, making the cutting chips tattered. However, it will reduce the shaping ability at high temperatures, causing uneven deformation and cracking during the process. Therefore, this study will discuss the high temperature mechanical properties of hot extruded Cu38Zn3Pb alloy, and study the mechanical properties, machinability and resistance to dezincification corrosion of hot extruded Cu38Zn3Pb alloy after hot rolling.
The results show that the hot extruded Cu38Zn3Pb alloy has higher tensile ductility at temperatures above 500 °C, but there exists a decreasing range of the impact toughness in the intermediate temperature, and which is the brittle effect. The impact toughness is not recovered until 700 °C. The Cu38Zn3Pb alloy undergoes dynamic recrystallization after hot rolling, which promote the refinement of the structure and the improvement of mechanical properties. In addition, as the deformation ratio increases, the hardness increases and affects the shape and size of the chips generated during cutting. Furthermore, the refinement of the structure and dislocation accumulated result in a decrease in the corrosion resistance of the alloy.
The hot-extruded Cu38Zn3Pb alloy exist the intermediate temperature embrittlement, and the ductility and toughness at high temperature are significantly improved. After drilling test, the requirements of continuous cutting conditions can be met, and relevant results can provide reference for copper industry application.

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