固溶温度对Al-Zn-Mg-Cu-Cr合金组织与性能的影响
Effect of Solution Temperature on Microstructure and Properties of Al-Zn-Mg-Cu-Cr Alloy
丰崇友, 唐普洪
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作者单位：(嘉兴职业技术学院 机电与汽车分院, 浙江 嘉兴 314036)
中文关键字：Al-Zn-Mg-Cu-Cr合金； 固溶； 性能； 组织
英文关键字：Al-Zn-Mg-Cu-Cr alloy; solution; properties; microstructure
中文摘要：采用电子拉伸试验机、显微硬度计、洛氏硬度计、扫描电镜(SEM)、能谱分析(EDS)等对不同固溶状态下Al-Zn-Mg-Cu-Cr超高强铝合金的硬度、力学性能及组织等进行了系统的研究。结果表明，随固溶温度的升高，合金的硬度和强度不断升高，在753 K时合金的综合性能最好，σb=577 MPa，σ0.2=521 MPa，δ=11.7%；但当温度高于758 K时，合金的硬度、强度急剧下降。组织观察表明，随固溶温度的升高，时效组织中的析出相数量不断增多，均匀程度也不断提高，密度也不断增大，颗粒也变得细小，但当温度达到763 K时，在合金组织内部能观察到明显的过烧现象，组织中出现复熔组织。另外，随固溶温度的升高，合金的应力腐蚀敏感性先不断降低，然后又急剧上升。其中，753 K时合金的应力腐蚀敏感性最低，只有17.36%，相对于713 K时的合金抗应力腐蚀性能提高了约51.2%。
英文摘要：The microstructure, hardness, strength and SCC susceptibility of Al-Zn-Mg-Cu-Cr alloy at different solution temperature were investigated by means of microhardness tester, rockwell hardometer, electronic tensile machine，SEM and EDS. The results show that hardness and strength of the alloy increase with the increase of solution temperature. The properties of the alloy solution-treated at 753 K are better that is, σb=577 MPa, σ0.2=521 MPa, δ=11.7%. However, when the solution temperature is up to 758 K, the hardness and strength of the alloy decline in high speed. The quantity, density, equality of the precipitate phase of the alloy improve with the increase of solution temperature. When the solution temperature is up to 763 K, compound-melting structure appears (namely burnt structure) in the alloys. The SCC susceptibility of the alloy increases firstl and then goes down with wide-rang, with the raising of solid solution temperature. The SCC susceptibility of the alloy solution-treated at 753 K is lowest, it is 17.36%, which is lower than that of the alloy solution-treated at 713 K by 51.2% approximately.