Microstructures and Mechanical Properties of Age Hardenable Cu-2.0wt%Be Alloy for Projection Welding Electrode

프로젝션 용접 전극을 위한 시효경화성 Cu-2.0wt%Be 합금의 미세조직과 기계적성질

  • 김광수 (순천향대학교 디스플레이.신소재공학과) ;
  • 김진용 (코리아세미텍(주))
  • Received : 2015.07.24
  • Accepted : 2015.08.18
  • Published : 2015.09.27


Evaluations of the microstructure and mechanical properties of age hardenable Cu-2.0wt%Be alloy are performed in order to determine whether it can be used as a welding electrode for projection welding. The microstructure examinations, hardness measurements, and tensile tests of selective aging conditions are conducted. The results indicate that the aging treatment with the fine-grained microstructure exhibits better hardness and high tensile properties than those of the coarse-grained microstructure. The highest hardness value and high tensile strength are obtained from the aged condition of $300^{\circ}C$ for 360 min due to the presence of the metastable ${\dot{\gamma}}$ precipitates on the grain boundaries. The values of the highest hardness and tensile strength are measured as 374 Hv and 1236.2 MPa, respectively. The metastable ${\dot{\gamma}}$ precipitates are transferred to the equilibrium ${\gamma}$ precipitates due to the over-aged treatment. The presence of the ${\gamma}$ precipitates appears as nodule-like precipitates decorated around the grain boundaries. The welding electrode with the best aging treated condition exhibits better welding performance for electrodes than those of electrodes used previously.


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