Improving the stress corrosion resistance of 7075 matrix composites through combination of nanoparticle incorporation and retrogression re-aging treatment

Shengxian Li, Yihong Wu, Wei Wang, Xuejian Wang, Huijun Kang, Enyu Guo, Jiehua LI, Yanjin Xu, Zongning Chen, Tongmin Wang

Research output: Contribution to journalArticleResearchpeer-review


7xxx aluminum matrix composites reinforced with ceramic nanoparticles are expected to possess advantageous comprehensive performance. However, further applications of these composites remain in doubt because it is likely that introducing these extrinsic phases could impair the resistance to stress corrosion crack (SCC). In this work, we used 7075 as the matrix, and TiB2 nanoparticles as the reinforcement, to study the influences of the retrogression and re-aging (RRA) treatment and nanoparticle incorporation on the SCC behavior of 7075 aluminum alloy. The intergranular corrosion test (IGCT) and slow strain rate test (SSRT) results show that both TiB2 and RRA are conducive to the improvements in the SCC resistance. The positive effects of RRA can be two-fold: (i) the lattice distortion is alleviated during the RRA temper; (ii) the coarse and discrete grain boundary precipitates (GBPs). The accumulation of active solute elements, however, also occurs at the grain boundaries, leading to severe intergranular corrosion. Surprisingly, some coarse TiB2 particles larger than the thickness of particle-free zones (PFZs) could obstruct the mass transportation, reducing the susceptibility to intergranular corrosion. In conclusion, the strength and SCC resistance of 7075 alloy can be concurrently improved by the combination of particle incorporation and RAA treatment.
Original languageEnglish
Article number106639
Number of pages10
JournalMaterials Today Communications
Issue numberAugust
Publication statusPublished - Aug 2023

Bibliographical note

Funding Information:
This work was supported by the National Key Research and Development Program of China (No. 2022YFB3400141 ), National Natural Science Foundation of China (Nos. 52174356, 52022017, 51927801, 51971051 and U22A20174 ), the Science and Technology Plan Project of Liaoning Province (Nos. 2022010005-JH6/1001 and 2022JH2/1013 ), the Innovation Foundation of Science and Technology of Dalian (Nos. 2020JJ25CY002 and 2020J12GX037 ) and the Fundamental Research Funds for the Central Universities . Jiehua Li acknowledges the financial support from Austrian Science Fund (FWF) ( P 32378-N37 ) and BMBWF ( KR 06/2020 ).

Publisher Copyright: © 2023 Elsevier Ltd


  • Aluminum matrix composites
  • Intergranular corrosion
  • Retrogression and re-aging
  • Stress corrosion cracking
  • TiB nanoparticles

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