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
Ti_(3)AlC_(2)was added into Cu-graphite composites to enhance their tribological properties.The impact of sintering temperature on properties of Cu-graphite-Ti_(3)AlC_(2)composites(CGTCs)fabricated by spark plasma sin...Ti_(3)AlC_(2)was added into Cu-graphite composites to enhance their tribological properties.The impact of sintering temperature on properties of Cu-graphite-Ti_(3)AlC_(2)composites(CGTCs)fabricated by spark plasma sintering(SPS)was studied,including microstructure,density,hardness,electrical conductivity,interfacial properties,and tribological behavior.The results indicate that mutual diffusion between Ti_(3)AlC_(2)and Cu occurs during sintering,leading to metallurgical bonding.Moreover,titanium atoms originating from Ti_(3)AlC_(2)undergo a reaction with carbon atoms on the graphite surface,facilitating enhanced bonding between Cu and graphite.CGTCs exhibit promising lubrication performance at different sintering temperatures,with friction coefficients ranging from 0.15 to 0.25.The wear rate decreases and then increases with the increase of sintering temperature.Optimal tribological properties are achieved at 980℃,when the average friction coefficient and wear rate are 0.18 and 4.82×10^(−6) mm^(3)·(N·m)^(−1),respectively.展开更多
Copper is a versatile material,commonly utilized in power transmission and electronic devices,but its relative high reactivity necessitates a long-lasting protective technique.Here,we report a method that combines pla...Copper is a versatile material,commonly utilized in power transmission and electronic devices,but its relative high reactivity necessitates a long-lasting protective technique.Here,we report a method that combines plasma-enhanced non-equilibrium magnetron sputtering physical vapor deposition(PEUMS-PVD)and anodization to construct a self-healing three-dimensional Ti/Al-doped TiO_(2)nanotubes/Ti_(3)AlC_(2)coating on the surface of Cu substrates.This novel strategy enhances the corrosion resistance of copper substrates in marine environments,with corrosion current densities of up to 4.5643×10^(−8)A/cm^(2).Among them,the doping of nano-aluminum particles makes the coating self-healing.The mechanistic analysis of the corrosion behaviors during early immersion experiments was conducted using electrochemical noise,and revealed that during the initial stages of coating immersion,uniform corrosion predominates,with a minor occurrence of localized corrosion.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Open subject of State Key Laboratory of Heavy-Duty and Express High-Power Electric Locomotive(QZKFKT2023-007)。
文摘Ti_(3)AlC_(2)was added into Cu-graphite composites to enhance their tribological properties.The impact of sintering temperature on properties of Cu-graphite-Ti_(3)AlC_(2)composites(CGTCs)fabricated by spark plasma sintering(SPS)was studied,including microstructure,density,hardness,electrical conductivity,interfacial properties,and tribological behavior.The results indicate that mutual diffusion between Ti_(3)AlC_(2)and Cu occurs during sintering,leading to metallurgical bonding.Moreover,titanium atoms originating from Ti_(3)AlC_(2)undergo a reaction with carbon atoms on the graphite surface,facilitating enhanced bonding between Cu and graphite.CGTCs exhibit promising lubrication performance at different sintering temperatures,with friction coefficients ranging from 0.15 to 0.25.The wear rate decreases and then increases with the increase of sintering temperature.Optimal tribological properties are achieved at 980℃,when the average friction coefficient and wear rate are 0.18 and 4.82×10^(−6) mm^(3)·(N·m)^(−1),respectively.
基金Projects(42106051,42006046,U2106206) supported by the National Natural Science Foundation of ChinaProject(22373501D) supported by Hebei Provincial Key R&D Program,China。
文摘Copper is a versatile material,commonly utilized in power transmission and electronic devices,but its relative high reactivity necessitates a long-lasting protective technique.Here,we report a method that combines plasma-enhanced non-equilibrium magnetron sputtering physical vapor deposition(PEUMS-PVD)and anodization to construct a self-healing three-dimensional Ti/Al-doped TiO_(2)nanotubes/Ti_(3)AlC_(2)coating on the surface of Cu substrates.This novel strategy enhances the corrosion resistance of copper substrates in marine environments,with corrosion current densities of up to 4.5643×10^(−8)A/cm^(2).Among them,the doping of nano-aluminum particles makes the coating self-healing.The mechanistic analysis of the corrosion behaviors during early immersion experiments was conducted using electrochemical noise,and revealed that during the initial stages of coating immersion,uniform corrosion predominates,with a minor occurrence of localized corrosion.
