A ternary system of PTFE/Al/Bi_(2)O_(3)is constructed by incorporating PTFE-based reactive material and thermite for enhancing the energy release of the PTFE-based reactive material.The effects of Bi_(2)O_(3)in the PT...A ternary system of PTFE/Al/Bi_(2)O_(3)is constructed by incorporating PTFE-based reactive material and thermite for enhancing the energy release of the PTFE-based reactive material.The effects of Bi_(2)O_(3)in the PTFE/Al/Bi_(2)O_(3)on both mechanical properties and the energy release were investigated through various tests such as thermogravimetry-differential scanning calorimetry,adiabatic oxygen bomb test and split Hopkinson pressure bar test.The microstructure observed through scanning electron microscope and Xray diffraction results are used to analyze the ignition and reaction mechanism of PTFE/Al/Bi_(2)O_(3).The results indicate that the PTFE/Al/Bi_(2)O_(3)are capable of triggering the exothermic reaction of molten PTFE/Bi_(2)O_(3)and Al/Bi_(2)O_(3)over the PTFE/Al reactive materials,thereby promoting reactions.The excessive aluminum in the ternary system is beneficial for increasing energy release.The ignition of shock-induced chemical reactions in PTFE/Al/Bi_(2)O_(3)is closely related to the material fracture.The dominant mechanism for hot-spot generation under Split Hopkinson Pressure Bar test is the frictional temperature rise at the microcrack after failure.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the National Natural Science Foundation of China (Grant No.12002045)State Key Laboratory of Explosion Science and Technology,Beijing Institute of Technology (Grant No.QNKT22-09)。
文摘A ternary system of PTFE/Al/Bi_(2)O_(3)is constructed by incorporating PTFE-based reactive material and thermite for enhancing the energy release of the PTFE-based reactive material.The effects of Bi_(2)O_(3)in the PTFE/Al/Bi_(2)O_(3)on both mechanical properties and the energy release were investigated through various tests such as thermogravimetry-differential scanning calorimetry,adiabatic oxygen bomb test and split Hopkinson pressure bar test.The microstructure observed through scanning electron microscope and Xray diffraction results are used to analyze the ignition and reaction mechanism of PTFE/Al/Bi_(2)O_(3).The results indicate that the PTFE/Al/Bi_(2)O_(3)are capable of triggering the exothermic reaction of molten PTFE/Bi_(2)O_(3)and Al/Bi_(2)O_(3)over the PTFE/Al reactive materials,thereby promoting reactions.The excessive aluminum in the ternary system is beneficial for increasing energy release.The ignition of shock-induced chemical reactions in PTFE/Al/Bi_(2)O_(3)is closely related to the material fracture.The dominant mechanism for hot-spot generation under Split Hopkinson Pressure Bar test is the frictional temperature rise at the microcrack after failure.
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%.
