外加入法制备高强高导Cu-Cr复合材料的研究
发布时间：2018-07-16 17:52
【摘要】：本文系统研究了外加入法Cu-5wt%Cr复合材料的制备及其组织与性能。通过试验优选出Cr颗粒的外加入方法和Cu-Cr复合材料铸锭的制备工艺。采用X射线衍射仪、金相显微镜及扫描电子显微镜等观察和分析了材料的微观组织结构,特别是第二相Cr颗粒在冷拔变形中逐步形成纤维状的组织演变规律;采用微机控制电子万能试验机、直流双臂电桥测试和分析了材料的力学性能和导电性能,重点研究了冷拔变形量及中间退火温度对材料强度和导电率的影响规律。研究结果表明:Cu-Cr复合材料铸锭的最佳制备方法为:采用真空感应熔炼法,以球磨CuCr混合粉末压制块形式将Cr颗粒外加入至铜的熔体中,辅之以熔体的人工搅拌,使Cr颗粒均匀分布于铜熔体中,随后再次抽真空脱除熔体中的气体,制备Cu-Cr复合材料铸锭。Cu-Cr材料在冷拔变形过程中,随着变形量的增加,材料中的Cr颗粒第二相被拉长,逐渐形成纤维状。由于原始组织的不均匀性,初期变形颗粒的取向差异和变形过程中第二相受到应力大小的不一致,导致Cr颗粒的变形是不均匀的。退火使Cu-Cr复合材料中的Cr纤维发生弯曲、粗化、溶断;退火温度越高,纤维的粗化、溶断现象越严重。Cu-Cr复合材料在冷拔变形过程中,随着变形量的增加,材料的抗拉强度提高,导电率降低。经过中间退火后,材料的抗拉强度降低,导电率提高。Cu-Cr复合材料在制备过程中,将材料的冷拔变形量与合理的中间退火工艺相组合,可以得到强度和导电率的良好配合,制备得到的Cu-5wt%Cr复合材料的抗拉强度达到640 MPa,导电率为61%IACS。
[Abstract]:The preparation, microstructure and properties of Cu-5wtCr composites by external addition method were studied systematically in this paper. The external addition method of Cr particles and the preparation process of Cu-Cr composite ingot were optimized by experiments. The microstructure of the material was observed and analyzed by means of X-ray diffractometer, metallographic microscope and scanning electron microscope, especially the evolution law of the second phase Cr particles gradually forming fibrous structure during cold drawing deformation. The mechanical properties and electrical conductivity of the materials were tested and analyzed by using a microcomputer controlled electronic universal testing machine. The effects of cold drawing deformation and intermediate annealing temperature on the strength and conductivity of the materials were studied. The results show that the optimum preparation method of Cu-Cr composite ingot is as follows: by vacuum induction melting, the Cr particles are added to the melt of copper in the form of ball milling CuCr mixed powder pressing block, supplemented by artificial stirring of the melt. The Cr particles are uniformly distributed in the copper melt, and then the gas in the melt is removed by vacuum again. During the cold drawing deformation of Cu-Cr composite ingot, the second phase of Cr particles in the material is elongated with the increase of the deformation amount. Gradually forming fibrous. Due to the inhomogeneity of the original structure, the orientation difference of the initial deformation particles and the inconsistency of the second phase stress during the deformation process lead to the inhomogeneous deformation of Cr particles. Annealing results in bending, coarsening and dissolution of Cr fibers in Cu-Cr composites. The higher annealing temperature, the thicker the fibers, the more serious the dissolution and fracture of Cu-Cr composites. During cold drawing deformation, the tensile strength of Cu-Cr composites increases with the increase of the amount of deformation. The conductivity is reduced. After intermediate annealing, the tensile strength of the material decreases, and the conductivity of the composite is increased. In the process of preparation, the cold drawing deformation of the material is combined with the reasonable intermediate annealing process, and the strength and conductivity of the composite can be well matched. The tensile strength of Cu-5wtCr composite is 640 MPA, and the conductivity is 61%.
【学位授予单位】：河北科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB33
本文编号：2127161
[Abstract]:The preparation, microstructure and properties of Cu-5wtCr composites by external addition method were studied systematically in this paper. The external addition method of Cr particles and the preparation process of Cu-Cr composite ingot were optimized by experiments. The microstructure of the material was observed and analyzed by means of X-ray diffractometer, metallographic microscope and scanning electron microscope, especially the evolution law of the second phase Cr particles gradually forming fibrous structure during cold drawing deformation. The mechanical properties and electrical conductivity of the materials were tested and analyzed by using a microcomputer controlled electronic universal testing machine. The effects of cold drawing deformation and intermediate annealing temperature on the strength and conductivity of the materials were studied. The results show that the optimum preparation method of Cu-Cr composite ingot is as follows: by vacuum induction melting, the Cr particles are added to the melt of copper in the form of ball milling CuCr mixed powder pressing block, supplemented by artificial stirring of the melt. The Cr particles are uniformly distributed in the copper melt, and then the gas in the melt is removed by vacuum again. During the cold drawing deformation of Cu-Cr composite ingot, the second phase of Cr particles in the material is elongated with the increase of the deformation amount. Gradually forming fibrous. Due to the inhomogeneity of the original structure, the orientation difference of the initial deformation particles and the inconsistency of the second phase stress during the deformation process lead to the inhomogeneous deformation of Cr particles. Annealing results in bending, coarsening and dissolution of Cr fibers in Cu-Cr composites. The higher annealing temperature, the thicker the fibers, the more serious the dissolution and fracture of Cu-Cr composites. During cold drawing deformation, the tensile strength of Cu-Cr composites increases with the increase of the amount of deformation. The conductivity is reduced. After intermediate annealing, the tensile strength of the material decreases, and the conductivity of the composite is increased. In the process of preparation, the cold drawing deformation of the material is combined with the reasonable intermediate annealing process, and the strength and conductivity of the composite can be well matched. The tensile strength of Cu-5wtCr composite is 640 MPA, and the conductivity is 61%.
【学位授予单位】：河北科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB33
【参考文献】
相关期刊论文 前1条
1 姜训勇，李忆莲，王童;高强度高导电铜合金[J];上海有色金属;1995年05期
，本文编号：2127161
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