关键词: 快速凝固, Cu-Ag-Zr合金, 室温力学性能, 高温力学性能, 析出相

Abstract: Rapidly solidified Cu-5Ag-0.5Zr and Cu-5Ag-0.5Zr-0.4Cr-0.35Nb (wt%) powders were compacted by hot sostatic pressing (HIP) and followed by hot forging and cold rolling.The mechanical properties of the alloy at room temperature and high temperature (500 ℃) were tested, and the microstructure and fracture morphology of the alloy were analyzed. The results show that cold rolled alloy has better room temperature tensile properties, and the ultimate tensile strength and elongation at room temperature of cold rolled Cu-Ag-Zr alloy are 739.3 MPa and 7.1%, respectively, which is related to the dense Cu₄AgZr and nano-sized Ag particles in Cu matrix. Apart from Cu₄AgZr and Ag particles, the addition of Cr and Nb elements generates high temperature stable Cr₂Nb particles, which enhances the tensile strength of the alloy at both room temperature and 500 ℃. The ultimate tensile strength and elongation at room temperature of cold rolled Cu-Ag-Zr-Cr-Nb alloy are 799.1 MPa and 5.3%, respectively. The hot forged alloy has a better weakening resistance at high temperature than that of cold rolled alloy due to larger grain size and finer Ag particles.The hot forged Cu-Ag-Zr-Cr-Nb and Cu-Ag-Zr alloys have a tensile strength of 186.8 MPa and 129.2 MPa at 500 ℃, respectively, while the tensile strength of cold rolled Cu-Ag-Zr-Cr-Nb and Cu-Ag-Zr alloys at 500 ℃ is only 113.1 MPa and 95.4 MPa, respectively.

Key words: rapidly solidified, Cu-Ag-Zr alloy, mechanical properties at room temperature, mechanical properties at high temperature, precipitates