Zr含量对Al-Zn-Mg-Cu超高强合金显微组织与性能的影响

Effect of Zr Content on Microstructure and Properties of Al-Zn-Mg-Cu Ultra-high Strength Alloy

通过OM、硬度测试、拉伸测试、晶间腐蚀测试等,研究了Zr含量对Al-Zn-Mg-Cu超高强合金显微组织与性能的影响。结果表明:Zr元素能细化Al-Zn-Mg-Cu合金的组织,具有抑制再结晶效果。在0.3%~0.6%Zr,随着Zr含量的增加,Al-Zn-Mg-Cu合金的晶粒细化效果逐渐增加,再结晶程度逐渐降低。对不同Zr含量的Al-Zn-Mg-Cu合金进行470℃×2 h固溶处理、水淬,再进行120℃×6 h+155℃×12 h的双级时效处理,随着Zr含量的增加,Al-Zn-Mg-Cu合金的抗拉强度、硬度、抗晶间腐蚀性能逐渐降低。Zr含量0.3%的合金抗拉强度、硬度达到最大值,分别为624 MPa、196 HV。

The effects of Zr content on the microstructure and properties of Al-Zn-Mg-Cu ultra-high strength alloy were studied by OM, hardness test, tensile test and intercrystalline corrosion test. The results show that Zr element can refine the microstructure of Al-Zn-Mg-Cu alloy and has the inhibitory effect on the recrystallization. In the range of 0.3%-0.6%Zr, the grain refinement effect of Al-Zn-Mg-Cu alloy gradually increases and the degree of recrystallization gradually decreases with the increases of Zr content. Al-Zn-Mg-Cu alloys with different Zr contents are treated by 470 ℃×2 h solid solution and water quenching, and then treated by 120 ℃ ×6 h +155 ℃ ×12 h dual-stage aging treatment. With the increase of Zr content, the tensile strength, hardness and intercrystalline corrosion resistance of Al-Zn-Mg-Cu alloys gradually decrease. The tensile strength and hardness of the alloy with Zr content of 0.3% reach the maximum value of 624 MPa and 196 HV, respectively.