微量co及熱處理對cu3.0ni0.75si合金組織性能的影響

1、分類號： 密 級：學(xué) 號： 6120100109 單位代碼： 10407碩 士 學(xué) 位 論 文論文題目: 微量 C C C Co o o o 及熱處理 及熱處理對 Cu-3.0Ni-0.75S Cu-3.0Ni-0.75S Cu-3.0Ni-0.75S Cu-3.0Ni-0.75Si i i i 合金 合金組織性能的影響 組織性能的影響研 究 方 向 銅合金加工技術(shù)開發(fā)與研究 銅合金加工技術(shù)開發(fā)與研究專 業(yè) 名 稱 材料學(xué) 材料學(xué)研 究

2、 生 姓 名 謝偉濱 謝偉濱導(dǎo)師姓名、職稱 柳瑞清 柳瑞清 教授 教授2013 年 5 月 29 日江西·贛州IIAbstract AbstractA series of experiments is performed for studying the effects of different contents of Co,hot-working technique, solution treatment, cold def

3、ormation or aging treatment on the hardness,electrical conductivity, tensile property softening temperature and the microstructure evolution ofCu-3.0Ni-0.75Si alloy ,by using X-ray diffraction(XRD), optical microscopy(OM

4、), scanningelectron microscopy(SEM), energy dispersive spectrometer (EDS).The results of the research show that the particle with high Ni, Si, Co content exist in thegrain and grain boundary of Cu-3.0Ni-0.75Si-xCo alloy

5、by hot rolling after holding 1h on 880℃.And the size of the particle in grain boundary is larger. The electrical conductivity of hor-rolledalloy increase rapidly at the first beginning and then decrease with the contents

6、 of Co increase.The cold rolling of 60% deformation ratios is carried after 950 ℃ × 1h solid solutiontreatment. After cold rolling the hardness increase due to working hardening effect, and theelectrical conductivit

7、y decrease slightly. During single aging treatment, the electrical conductivityincrease with the increase of the aging time due to the secondary phase precipitation. As a resultof the pinning effect of the precipitates o

8、n the dislocations, the hardness increase with theincrease of the aging time. Then the hardness decrease with the aging time continuous increasingdue to overaging. The Avrami phase transformation kinetics equation were d

9、erived by use of thelinearity between electrical conduetivity and volume fraction of precipitates under the agingproeess.The electrical conductivity of Cu-3.0Ni-0.75Si-xCo alloy, after 450℃×2h aging treatment,60% se

10、cond cold rolling and two-step aging treatment, is significantly higher than a single agingprocess. the electrical conductivity increase rapidly at the first beginning and then level out withthe increase of the two-step

11、aging time due to solute atoms precipitate. the electrical conductivityincrease rapidly at the first beginning and then decrease with the increase of the two-step agingtemperature. As a result of Coarsening of the precip

12、itated phase the hardness decrease with theincrease of the two-step aging temperature.The contents of Si in copper matrix decrease due to the CoSi phase precipitation, and theelectrical conductivity increase. As a result

13、 of the contents of Co continuous increasing thecontents of Co in copper matrix increase, and the electrical conductivity decrease. The hardness,tensile strength and softening temperature of Cu-3.0Ni-0.75Si alloy increas

14、e with the contents ofCo increase. the good properties of Cu-3.0Ni-0.75Si-0.2Co alloy can be obtained after 950℃×1h solid solution treatment, 60% cold rolling rate, 450 ℃ × 2h aging treatment, second coldrollin

15、g and 450℃×2h two-step aging treatment. The finish strip’s hardness is 213HB, electricconductivity is 48.7%IACS, tensile strength is 816MPa, elongation is 4.8%, and softeningtemperature is 430℃.K K K Key ey ey ey Wo