(中南大學(xué) 粉末冶金國家重點實驗室，長沙 410083)
摘 要: 通過金相顯微分析、硬度、強度和應(yīng)力腐蝕性能的測試，研究添加微量Cr和Nb 對Al-Zn-Mg-Cu-Zr 合金力學(xué)性能、再結(jié)晶與應(yīng)力腐蝕行為的影響。結(jié)果表明，在Al-Zn-Mg-Cu-Zr合金中添加微量Cr和Nb能提高合金的抑制再結(jié)晶能力，并顯著提高合金的抗應(yīng)力腐蝕性能，使合金在保持高的強度和塑性的同時，應(yīng)力腐蝕臨界應(yīng)力強度因子KISCC 由9.8 MPa∙m1/2提高到15.2 MPa∙m1/2。
關(guān)鍵字: Al-Zn-Mg-Cu-Zr合金；力學(xué)性能；再結(jié)晶；應(yīng)力腐蝕
（State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China）
Abstract:The effects of Cr and Nb additions on mechanical and stress corrosion cracking properties of Al-Zn-Mg-Cu-Zr aluminium alloy were investigated by microscopy, hardness, tensile test and stress corrosion cracking test. The results show that the Cr and Nb additions to high strength Al-Zn-Mg-Cu-Zr aluminum alloys can significantly inhibite recrystallization during solution treatment. The tensile and yield strengths, elongation, hardness, stress corrosion cracking resistance of the Cr and Nb containing alloys are moderately improved, comparing with the alloys without Cr and Nb additions. By Cr and Nb additions the critical stress intensity (KISCC) is enhanced from 9.8 MPa∙m1/2 up to 15.2 MPa∙m1/2 with maintaining high strength and ductility.
Key words: Al-Zn-Mg-Cu-Zr alloy; mechanical properties; recrystallization; stress corrosion
