Mn含量及退火工艺对Cu-xMn-0.2Ce-0.2Zr合金组织性能的影响

Effects of Mn content and annealing process on microstructure and properties of Cu-xMn-0.2Ce-0.2Zr alloys

采用显微组织观察和X射线衍射分析,通过电阻率和电阻温度系数、显微维氏硬度及Tafel极化曲线测量,研究了Mn含量及退火工艺对冷轧Cu-xMn-0.2Ce-0.2Zr(x=5、6、7、8)合金组织性能的影响。结果表明,随着Mn含量的增加,电阻率逐渐增加,电阻温度系数逐渐降低,且合金的择优取向均为(220)_(Cu)晶面。在250、350、450和550℃退火后,合金发生回复和再结晶,使得内应力降低,显微维氏硬度随着退火温度的升高和保温时间的延长而下降。当Mn含量为7%时,Cu-7Mn-0.2Ce-0.2Zr合金得到良好的综合性能。经350℃退火1 h、水冷后,电阻率为22.3μΩ·cm,电阻温度系数(TCR_(25-125℃))为116×10^(-6)℃^(-1)。自腐蚀电位和自腐蚀电流密度分别为-0.172 V和1.86μA/cm^(2)。说明Cu-7Mn-0.2Ce-0.2Zr合金在工作温度范围内具有优良的电学性能,同时也兼具较好的耐蚀性能。

Effects of Mn content and annealing process on microstructure and properties of cold-rolled Cu-xMn-0.2Ce-0.2Zr(x=5,6,7,8)alloys were studied by microstructure observation,X-ray diffraction analysis,and measurements of resistivity and temperature coefficient of resistance,micro Vickers hardness and Tafel polarization curves.The results show that with the increase of Mn content,the resistivity gradually increases,the temperature coefficient of resistance gradually decreases,and the preferential orientation of the alloy is(220)_(Cu) crystal plane.After annealing at 250,350,450 and 550℃,the alloy recovers and recrystallizes,so that the internal stress is reduced,and the micro Vickers hardness decreases with the increase of annealing temperature and the extension of holding time.When the Mn content is 7%,the alloy gets good comprehensive properties.After annealing at 350℃for 1 h and water cooling,the resistivity is 22.3μΩ·cm,and the temperature coeficient of resistance(TCR_(25-125℃))is 16×10^(-6)/℃.The self corosion potential and self corosion curent densty are-0.172 V and 1.86μA/cm^(2),respectively,indicating that the Cu-7Mn-0.2Ce-0.2Zr alloy has excellent electrical properties in the working temperature range,and also has good corrosion resistance.