喷射沉积超高强铝合金成分筛选与性能优化研究

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中图分类号：TQ028.8 文献标志码：A

Composition screening and performance optimization of spray deposition ultra high strength aluminum alloy

ZHENGXinyi，HANYu，ZHANGGuowei （School of Mechanical and Automotive Engineering，Ningbo University of Tecnology，Ningbo 315336，Zhejiang，China）

Abstract： In this paper， ultrahigh strength aluminum alloy was prepared by jet deposition technology. The microstructure and mechanical properties of the alloy were studied by electron microscope， scanning electron microscope JSM256ooLV， transmission electron microscope，rainbow machine，universal tensile machine and differential thermal scanner. The results show that after peak aging heat treatment， the microstructure of the alloy is uniform and fine the average grain size was 3～5μm ，and the Mg -rich and Ni-rich phases were precipitated along the crystal. The alloying element Mg can accelerate the occurrence of stress corrosion， the morphology of the precipitated phase of MgZn2 is short rod，and the morphology of the tensile fracture after heat treatment is a mixed fracture along the crystal and ligament fracture. At peak aging，the highest strength of the alloy reaches 850MPa and the elongation reaches 3. 25% . The final extrusion temperature adopts 390～410∘C ，the extrusion ratio is 6. 25，and the ingot is extruded into an aluminum rod， eliminating 2%～3% of pores to achieve complete densification.

Key words：jetde position；mechanical properties;microstructure

0 引言

超高强铝合金的概念常指屈服强度大于500MPa 的铝合金，其中以牌号为7系列的超硬铝最为典型。（剩余10985字）