| 摘要: | 本研究以光學顯微鏡(OM)、差式掃描熱分析儀(DSC)、導電度量測(%IACS)、電子顯微鏡(TEM、SEM)、硬度量測(HRB)、拉伸試驗(MTS)、慢應變速率拉伸試驗(SSRT)、剝落腐蝕(EXCO)等量測分析，來探討時效製程(自然時效與人工時效)對固溶淬火後之AA2024(Al-4.4Cu-1.5Mg)高強度鋁合金應力腐蝕與剝落腐蝕之影響；結果顯示，在T6態與T7態狀況下，合金之導電度、機械性質、剝落腐蝕與應力腐蝕等並不受自然時效的影響，然而T7態相較T6態具有明顯提升抗剝落腐蝕與應力腐蝕的效果，其剝落腐蝕深度由T6態的480μm，大幅降至T7態的220μm。而慢應變速率拉伸下的延性損失率，顯示合金抗應力腐蝕由T6態的70%，降至T7態的34%，這些結果均顯現自然時效對AA2024合金的機械性質與抗腐蝕性並無顯著的影響，但經T7熱處理後，合金之抗腐蝕能力明顯優於T6態合金。;In this study, optical microscope (OM), differential scanning thermal analyzer (DSC), conductivity measurement (%IACS), electron microscope (TEM, SEM), hardness measurement (HRB), tensile test (MTS), slow strain rate tensile test (SSRT), exfoliation corrosion (EXCO) and other measurement analysis to discuss the aging process (natural aging and artificial aging) on the influence of stress corrosion and exfoliation corrosion of AA2024 (Al-4.4Cu-1.5Mg) high strength aluminum alloys after solution quenching; the results show that in the T6 state and T7 state, the electrical conductivity, mechanical properties, exfoliation corrosion and stress corrosion of the alloy are not affected by natural aging, but the T7 state is compared to the T6 state, it can obviously improve the effect of anti-exfoliation corrosion and anti-stress corrosion, and the depth of exfoliation corrosion is greatly reduced from 480μm in T6 state to 220μm in T7 state. In the slow strain rate tensile test, the ductility loss rate of stress corrosion resistance of the alloy decreased from 70% in the T6 state to 34% in the T7 state. These results show that natural aging has no significant effect on the mechanical properties and corrosion resistance of the AA2024 alloy, but after T7 heat treatment, the corrosion resistance of the alloy is significantly better than T6 alloy. |
