Enhanced age-hardening behavior in Al–Cu alloys induced by in-situ synthesized TiC nanoparticles
来源期刊：JOURNAL OF MATERIALS SCIENCE TECHNOLOG2019年第3期
论文作者：Huabing Yang Tong Gao Huaning Zhang Jinfeng Nie Xiangfa Liu
文章页码：374 - 382
摘 要：The influence of in-situ synthesized TiC nanoparticles on age-hardening behavior of Al–Cu alloys was investigated in Al–4.5 Cu–1.5 TiC alloy. It was found that TiC nanoparticles decrease the peak-age time effectively, from about 20 h for Al–4.5 Cu alloy decreasing to about 12 h for the Al–4.5 Cu–1.5 TiC. Mechanical property test shows that the age-hardening effect has been improved by the TiC nanoparticles. The increment of yield strength before and after aging is about 84 MPa for Al–4.5 Cu, while, it reaches to about113 MPa for the Al–4.5 Cu–1.5 TiC. After aging heat treatment, precipitates have been observed both in matrix and around TiC nanoparticles. Due to the difference of coefficient of thermal expansion between TiC and Al, high density dislocations in the Al–4.5 Cu–1.5 TiC were generated during water quenching after solution. Dislocations play a role of diffusion path for Cu atoms during aging, which reduces the peak-age time. Alpha-Al lattice distortion resulted from lattice mismatch of TiC/Al interface induces the precipitation of θ’ phase around TiC nanoparticles, which increases the number density of θ’ and improves the age-hardening effect. This finding is supposed to be also applicable to alloy systems of Al–Cu–Mg,Al–Cu–Mg–Li, Al–Cu–Mg–Ag, etc.
Huabing Yang1，Tong Gao1，Huaning Zhang1，Jinfeng Nie2，Xiangfa Liu1
1. Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials, Ministry of Education, Shandong University2. Nano Structural Materials Center, School of Materials Science and Engineering, Nanjing University of Science and Technology
摘 要：The influence of in-situ synthesized TiC nanoparticles on age-hardening behavior of Al–Cu alloys was investigated in Al–4.5 Cu–1.5 TiC alloy. It was found that TiC nanoparticles decrease the peak-age time effectively, from about 20 h for Al–4.5 Cu alloy decreasing to about 12 h for the Al–4.5 Cu–1.5 TiC. Mechanical property test shows that the age-hardening effect has been improved by the TiC nanoparticles. The increment of yield strength before and after aging is about 84 MPa for Al–4.5 Cu, while, it reaches to about113 MPa for the Al–4.5 Cu–1.5 TiC. After aging heat treatment, precipitates have been observed both in matrix and around TiC nanoparticles. Due to the difference of coefficient of thermal expansion between TiC and Al, high density dislocations in the Al–4.5 Cu–1.5 TiC were generated during water quenching after solution. Dislocations play a role of diffusion path for Cu atoms during aging, which reduces the peak-age time. Alpha-Al lattice distortion resulted from lattice mismatch of TiC/Al interface induces the precipitation of θ’ phase around TiC nanoparticles, which increases the number density of θ’ and improves the age-hardening effect. This finding is supposed to be also applicable to alloy systems of Al–Cu–Mg,Al–Cu–Mg–Li, Al–Cu–Mg–Ag, etc.
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