The properties of the combustion and deflagration to detonation transition(DDT)of Al/Fe_(2)O_(3)/RDX hybrid nanocomposites,a type of potentially novel lead-free primary explosives,were tested in weakly confined condit...The properties of the combustion and deflagration to detonation transition(DDT)of Al/Fe_(2)O_(3)/RDX hybrid nanocomposites,a type of potentially novel lead-free primary explosives,were tested in weakly confined conditions,and the interaction of Al/Fe_(2)O_(3)nanothermite and RDX in the DDT process was studied in detail.Results show that the amount of the Al/Fe_(2)O_(3)nanothermite has a great effect on the DDT properties of Al/Fe_(2)O_(3)/RDX nanocomposites.The addition of Al/Fe_(2)O_(3)nanothermite to RDX apparently improves the firing properties of RDX.A small amount of Al/Fe_(2)O_(3)nanothermite greatly increases the initial combustion velocity of Al/Fe_(2)O_(3)/RDX nanocomposites,accelerating their DDT process.When the contents of Al/Fe_(2)O_(3)nanothermite are less than 20 wt%,the DDT mechanisms of Al/Fe_(2)O_(3)/RDX nanocomposites follow the distinct abrupt mode,and are consistent with that of RDX,though their DDT processes are different.The RDX added into the Al/Fe_(2)O_(3)nanothermite increases the latter's peak combustion velocity and makes it generate the DDT when the RDX content is at least 10 wt%.RDX plays a key role in the shock compressive combustion,the formation and the properties of the DDT in the flame propagation of nanocomposites.Compared with RDX,the fast DDT of Al/Fe_(2)O_(3)/RDX nanocomposites could be obtained by adjusting the chemical constituents of nanocomposites.展开更多
On October 13,2020,on the fairway connecting the Polish Baltic ports ofSwinoujscie and Szczecin,an underwater hazardous object of historical origin in the form of the British deep penetration bomb Tallboy dropped duri...On October 13,2020,on the fairway connecting the Polish Baltic ports ofSwinoujscie and Szczecin,an underwater hazardous object of historical origin in the form of the British deep penetration bomb Tallboy dropped during the bombing of the German cruiser"Lützow"in April 1945 was neutralized successfully.It is believed to be the first underwater action concerning this type of bomb,which has previously been neutralized on land in Europe(Germany,one confirmed case).The preparation of the operation,on an unprecedented scale at national,European and global level,took one year and included a series of projects related to clearing the space around the bomb from other identified UXO objects,international consultations,historical analyses,determination of the risk to residents and critical infrastructure in the event of an explosion of the bomb containing approximately 2400 kg of the TORPEX explosive(with an increased force equivalent to almost 3600 kg of TNT).The object was neutralized on spot at the depth of 12 m,near a ferry crossing,by specialists from the 41st Navy EOD Team from the 12th MCM Squadron(8th Coastal Defence Flotilla),using the Low Order Deflagration technique(underwater deflagration method).In the case discussed,there was an accumulation of unfavourable conditions which practically excluded the use of blow-in-situ explosive methods(BIP),as well as the extraction of the object and its transport to a military ground.After a partial deflagration of the explosive,the explosive was detonated(DDT).Estimates indicate that the deflagration level reached between 55 and 60%,which significantly reduced the strength and effects of the underwater explosion.展开更多
基金supported by National Nature Science Foundation of China(No.22075230)the financial support of the doctoral research foundation(No.19ZX7102)from Southwest University of Science and Technology。
文摘The properties of the combustion and deflagration to detonation transition(DDT)of Al/Fe_(2)O_(3)/RDX hybrid nanocomposites,a type of potentially novel lead-free primary explosives,were tested in weakly confined conditions,and the interaction of Al/Fe_(2)O_(3)nanothermite and RDX in the DDT process was studied in detail.Results show that the amount of the Al/Fe_(2)O_(3)nanothermite has a great effect on the DDT properties of Al/Fe_(2)O_(3)/RDX nanocomposites.The addition of Al/Fe_(2)O_(3)nanothermite to RDX apparently improves the firing properties of RDX.A small amount of Al/Fe_(2)O_(3)nanothermite greatly increases the initial combustion velocity of Al/Fe_(2)O_(3)/RDX nanocomposites,accelerating their DDT process.When the contents of Al/Fe_(2)O_(3)nanothermite are less than 20 wt%,the DDT mechanisms of Al/Fe_(2)O_(3)/RDX nanocomposites follow the distinct abrupt mode,and are consistent with that of RDX,though their DDT processes are different.The RDX added into the Al/Fe_(2)O_(3)nanothermite increases the latter's peak combustion velocity and makes it generate the DDT when the RDX content is at least 10 wt%.RDX plays a key role in the shock compressive combustion,the formation and the properties of the DDT in the flame propagation of nanocomposites.Compared with RDX,the fast DDT of Al/Fe_(2)O_(3)/RDX nanocomposites could be obtained by adjusting the chemical constituents of nanocomposites.
文摘On October 13,2020,on the fairway connecting the Polish Baltic ports ofSwinoujscie and Szczecin,an underwater hazardous object of historical origin in the form of the British deep penetration bomb Tallboy dropped during the bombing of the German cruiser"Lützow"in April 1945 was neutralized successfully.It is believed to be the first underwater action concerning this type of bomb,which has previously been neutralized on land in Europe(Germany,one confirmed case).The preparation of the operation,on an unprecedented scale at national,European and global level,took one year and included a series of projects related to clearing the space around the bomb from other identified UXO objects,international consultations,historical analyses,determination of the risk to residents and critical infrastructure in the event of an explosion of the bomb containing approximately 2400 kg of the TORPEX explosive(with an increased force equivalent to almost 3600 kg of TNT).The object was neutralized on spot at the depth of 12 m,near a ferry crossing,by specialists from the 41st Navy EOD Team from the 12th MCM Squadron(8th Coastal Defence Flotilla),using the Low Order Deflagration technique(underwater deflagration method).In the case discussed,there was an accumulation of unfavourable conditions which practically excluded the use of blow-in-situ explosive methods(BIP),as well as the extraction of the object and its transport to a military ground.After a partial deflagration of the explosive,the explosive was detonated(DDT).Estimates indicate that the deflagration level reached between 55 and 60%,which significantly reduced the strength and effects of the underwater explosion.
