Ti2AlC triggered in-situ ultrafine TiC/Inconel 718 composites:Microstructure and enhanced properties

• 作者: Wenqiang Hu Zhenying Huang Qun Yu Yuanbo Wang Yidan Jiao Cong Lei Leping Cai Hongxiang Zhai Yang Zhou
• 来源期刊: 材料科学技术（英文版）
• 年，卷（期）: 2020,（16）
• 页码范围: 70-78
• 页数: 9页
• 语种: 英文

摘要

In situ ultrafine TiC dispersion reinforced Inconel 718 alloy with enhanced mechanical properties was fabricated by the technique of reactive hot-press sintering Ti2AlC and In718 powders.The effect of Ti2AlC precursor additions (5 vol.％,10 vol.％,15 vol.％) on microstructure and mechanical properties of TiC/In718 composites were investigated.A relationship of microstructural characteristics,room and elevated tem-perature mechanical performance,and underlying strengthening mechanisms were analyzed.The results show that initial Ti2AlC precursor transformed completely into ultrafine TiC particulate (～230 nm) and distributed uniformly in the matrix after sintering 5 and 10 vol.％ Ti2AlC/In718.However,TiC particulates tended to aggregate to stripes with the addition of Ti2AlC up to 15 vol.％,which,in adverse,weaken the properties of In718.The 5 vol.％ Ti2AlC/In718 sample showed a higher tensile strength of 1404 ± 13 MPa with a noticeable elongation of 9.8％ at room temperature compared to the pure In718 (ultimate tensile strength (UTS) =1310 MPa,elongation =21.5％).At 600 ℃,700 ℃,800 ℃ and 900 ℃,tensile strength of the as-sintered 5 vol.％ Ti2AlC/In718 composite was determined to be 1333 ± 13 MPa,1010 ±10 MPa,685 ± 25 MPa and 276 ± 3 MPa,increased by 9.2％,14.6％,14.2％ and 55％,respectively,compared with that of monolithic In718 alloy.The excellent tensile properties of TiC/In718 composite can be ascribed to the combined mechanisms in term of increased dislocation density,dispersive Orowan and load transfer mechanisms.