In this paper, a self-propagating high-temperature combustion synthesis with the pseudo-hot isostatic pressing process（SHS/PHIP） was employed to fabricate high-pure Ti_3AlC_2（φ 240 mm）. In addition, the first pri...In this paper, a self-propagating high-temperature combustion synthesis with the pseudo-hot isostatic pressing process（SHS/PHIP） was employed to fabricate high-pure Ti_3AlC_2（φ 240 mm）. In addition, the first principle with quasi-harmonic approximation was applied for the thermodynamic properties＇ investigation of Ti_2AlC and Ti_3AlC_2, including Gibbs free energy, enthalpy, and entropy.With temperature increasing, Gibbs free energy increases,but enthalpy and entropy decrease. The present work provides the theoretical proof for the synthesis mechanism of Ti_3AlC_2 by SHS/PHIP.展开更多
The oxidation behavior of Ti_3AlC_2-20 TiB_2 composite was studied at 500℃–900℃ in air. The composite showed a very low oxidation rate and followed a logarithmic oxidation law. The in-situ incorporation of TiB_2 su...The oxidation behavior of Ti_3AlC_2-20 TiB_2 composite was studied at 500℃–900℃ in air. The composite showed a very low oxidation rate and followed a logarithmic oxidation law. The in-situ incorporation of TiB_2 suppressed the anomalous rapid oxidation of the substrate Ti_3AlC_2 occurred near 600℃ by forming a protective B_2O_3 glass layer, and also improved the oxidation resistance of the MAX phase at intermediatetemperature.展开更多
The interfacial reaction behavior of Al and Ti_(3)AlC_(2)at different pouring temperatures and its effect on the microstructure and mechanical properties of the composites were investigated.The results show that the a...The interfacial reaction behavior of Al and Ti_(3)AlC_(2)at different pouring temperatures and its effect on the microstructure and mechanical properties of the composites were investigated.The results show that the addition of3.0 wt.%Ti_(3)AlC_(2)refines the average grain size ofα(Al)in the composite by 50.1%compared to Al6061 alloy.Morphological analyses indicate that an in-situ Al_(3Ti)transition layer of-180 nm in thickness is generated around the edge of Ti_(3)AlC_(2)at 720℃,forming a well-bonded Al-Al_(3Ti)interface.At this processing temperature,the ultimate tensile strength of A16061-3.0 wt.%Ti_(3)AlC_(2)composite is 199.2 MPa,an improvement of 41.5%over the Al6061 matrix.Mechanism analyses further elucidate that 720℃is favourable for forming the nano-sized transition layer at the Ti_(3)AlC_(2)edges.And,the thermal mismatch strengthening plays a dominant role in this state,with a strengthening contribution of about 74.8%.展开更多
基金financially supported by the National Natural Science Foundation of China (No. 51172057)the Science Innovate Talents Special Foundation of Harbin (No. 2011RXXG011)the Key Laboratory of Functional Inorganic Material Chemistry (Heilongjiang University), Ministry of Education
文摘In this paper, a self-propagating high-temperature combustion synthesis with the pseudo-hot isostatic pressing process（SHS/PHIP） was employed to fabricate high-pure Ti_3AlC_2（φ 240 mm）. In addition, the first principle with quasi-harmonic approximation was applied for the thermodynamic properties＇ investigation of Ti_2AlC and Ti_3AlC_2, including Gibbs free energy, enthalpy, and entropy.With temperature increasing, Gibbs free energy increases,but enthalpy and entropy decrease. The present work provides the theoretical proof for the synthesis mechanism of Ti_3AlC_2 by SHS/PHIP.
基金partially supported by the National Natural Science Foundation of China (No. 51102125, No. 51571205 and 51602140)the Foundation of Liaoning Educational Committee of China (No. LYB201618)partially by Foundation of Liaoning Province of China (No. 20170520130)
文摘The oxidation behavior of Ti_3AlC_2-20 TiB_2 composite was studied at 500℃–900℃ in air. The composite showed a very low oxidation rate and followed a logarithmic oxidation law. The in-situ incorporation of TiB_2 suppressed the anomalous rapid oxidation of the substrate Ti_3AlC_2 occurred near 600℃ by forming a protective B_2O_3 glass layer, and also improved the oxidation resistance of the MAX phase at intermediatetemperature.
基金financially supported by the National Natural Science Foundation of China(No.51965040)Science and Technology Project of Jiangxi Provincial Department of Transportation,China(No.2022H0048)。
文摘The interfacial reaction behavior of Al and Ti_(3)AlC_(2)at different pouring temperatures and its effect on the microstructure and mechanical properties of the composites were investigated.The results show that the addition of3.0 wt.%Ti_(3)AlC_(2)refines the average grain size ofα(Al)in the composite by 50.1%compared to Al6061 alloy.Morphological analyses indicate that an in-situ Al_(3Ti)transition layer of-180 nm in thickness is generated around the edge of Ti_(3)AlC_(2)at 720℃,forming a well-bonded Al-Al_(3Ti)interface.At this processing temperature,the ultimate tensile strength of A16061-3.0 wt.%Ti_(3)AlC_(2)composite is 199.2 MPa,an improvement of 41.5%over the Al6061 matrix.Mechanism analyses further elucidate that 720℃is favourable for forming the nano-sized transition layer at the Ti_(3)AlC_(2)edges.And,the thermal mismatch strengthening plays a dominant role in this state,with a strengthening contribution of about 74.8%.
