IMX-101

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IMX-101 is a high-performance insensitive high explosive composite mixture developed by BAE Systems and the United States Army to replace TNT in artillery shells. [1] [2] [3] [4] IMX stands for "Insensitive Munitions eXplosives", which refers to the purpose of IMX-101: to provide explosive force equivalent to TNT without its sensitivity to shocks such as gunfire, explosions from improvised explosive devices, fire, and shrapnel. For example, it is believed that a training incident in Nevada which killed seven Marines would not have occurred with the new explosive. On March 23, 2013, the United States Army ordered $780 million worth of the explosive, with a production of millions of pounds annually, to be produced by BAE at Holston Army Ammunition Plant in Tennessee. [5] The new explosive will cost $8 per pound, compared to $6 per pound for TNT. [6] As of 2023, IMX-101 filled shells are being used in the 2022 Russian invasion of Ukraine. [7]

Contents

IMX-101 pellets IMX-101.jpg
IMX-101 pellets

Time Magazine called IMX-101 one of the "50 best inventions of 2010". [6]

Composition

IMX-101 is composed of 2,4-dinitroanisole (DNAN), nitrotriazolone (NTO), and nitroguanidine (NQ). [5] The nominal composition is 43.5 wt% DNAN, 36.8 wt% NQ, and 19.7 wt% NTO. [8] [9] [10] Trace amounts of N-methyl-p-nitroaniline (MNA) are included in some formulations to aid in processing. [11] [12] A formulation containing about 24 wt% aluminum and 76 wt% IMX-101 is called ALIMX-101 and is currently being investigated as an insensitive replacement for H6 and PBXN-109 in Mk82-style bombs. [13]

A Family of Insensitive Melt Cast Explosive Formulations: Insensitive Melt Cast Explosives manufactured at Holston Army Ammunition Plant [9]
FormulationKey IngredientsReplacesPurposeQualification Status (2012)
IMX-101DNAN + NTO + NQTNTArtillery and other large caliber munitionsMaterial qualified; Type qualified for 155mm M795, on-going for 155mm M1122 and 105mm projectiles
IMX-104DNAN + NTO + RDX Comp B Mortar applicationsMaterial qualified; Type qualification on-going for 81mm mortar, 60mm & 120mm to follow
PAX-48DNAN + NTO + HMX Comp BMortar and tank ammunitionMaterial qualified; Type qualification achieved for 120mm IM HE-T tracer round (NAMMO)
OSX-12DNAN + NTO + RDX + Al PAX-28 High blast applicationsMaterial under evaluation
PAX-21 Picatinny arsenal explosiveDNAN + RDX + AP + MNA (N-methyl-p-nitroaniline)Main fill for the 60mm M768 Mortar RoundsCurrently in-use in theater
PAX-41DNAN + RDX + MNAMain fill for the Spider Grenade, thus a low critical diameter is required. [14]

The performance of PAX-28, a thermobaric, containing a mixture of RDX, DNAN, Al, AP and MNA was found to have an indoor explosive equivalency factor of 1.62 when compared to Composition B. [12] OSX-12 is being studied as a replacement to PAX-28.[ citation needed ]

Processing

Like Composition B, IMX formulations are melt-castable without thermal degradation, and are thus processed into munitions by a melt pour process starting with a batch melt kettle heated by a steam heat exchanger. [15] [16]

See also

Further reading

References

  1. "BAE IMX-101 Explosive Approved To Replace TNT In US Army Artillery". Archived from the original on 2010-08-07. Retrieved 2010-08-03.
  2. DTIC Background and Introduction to IMX-101, -102 and -103 Archived 2010-08-15 at the Wayback Machine
  3. The Application of New IM Explosive Candidates - DTIC Online Archived 2012-10-03 at the Wayback Machine
  4. "Army Approves Safer Explosive To Replace TNT". Archived from the original on 2010-08-20. Retrieved 2010-08-17.
  5. 1 2 Allison Barrie (2013-03-26). "Bye bye, TNT: New generation of explosives for the Army". Fox News. Archived from the original on 2013-03-27. Retrieved 2013-03-26.
  6. 1 2 Mark Thompson (2010-11-13). "Less Dangerous Explosives". Time Magazine. Archived from the original on 2013-05-25. Retrieved 2013-06-16.
  7. Ismay, John; Keyssar, Natalie; French, Lyndon; Taylor, Marisa Schwartz; Lieberman, Rebecca (2023-02-02). "How to Forge Shells for Ukraine's Artillery". The New York Times. ISSN   0362-4331 . Retrieved 2023-02-02.
  8. Koch, Ernst-Christian (August 2019). "E.-C. Koch, Insensitive High Explosives: IV. Nitroguanidine - Initiation & Detonation, Defence Technol.2019, 15, 467-487". Defence Technology. 15 (4): 467–487. doi: 10.1016/j.dt.2019.05.009 .
  9. 1 2 This table is closely modelled on Virgil Fung; et al. (2012). "2012 IMEMTS, Las Vegas, NV (S2DSEA2012-0148) Process Improvement and Optimization of Insensitive Explosive IMX-101 2012 Insensitive Munitions & Energetic Material Technology Symposium" (PDF). U.S. Army. Archived (PDF) from the original on 2021-01-25. Retrieved 2021-01-25.
  10. Cuddy, Michael F.; Poda, Aimee R.; Chappell, Mark A. (2014). "Estimations of Vapor Pressures by Thermogravimetric Analysis of the Insensitive Munitions IMX-101, IMX-104, and Individual Components". Propellants, Explosives, Pyrotechnics. 39 (2): 236–242. doi:10.1002/prep.201300069.
  11. Rao, Balaji; Wang, Wei; Cai, Qingsong; Anderson, Todd; Gu, Baohua (2013). "Photochemical transformation of the insensitive munitions compound 2,4-dinitroanisole". Science of the Total Environment. 443: 692–699. Bibcode:2013ScTEn.443..692R. doi:10.1016/j.scitotenv.2012.11.033. PMID   23228715.
  12. 1 2 "Insenstive High Explosives (IHE)". Archived from the original on 2014-07-08. Retrieved 2014-06-04.
  13. "The Latest from Defense Systems Information Analysis Center" (PDF). Defense System Digest. March 12, 2019. Archived (PDF) from the original on June 11, 2020. Retrieved January 25, 2021.
  14. "DEVELOPMENT & OPTIMIZATION OF A PRODUCTION METHOD FOR MANUFACTURING PAX-41" (PDF). Archived from the original (PDF) on July 19, 2013.
  15. "IMX-104 High Explosive (HE) Loading of 81mm & 120mm Mortars" (PDF). Archived from the original (PDF) on 2014-06-04.
  16. Ismay, John; Keyssar, Natalie; French, Lyndon; Taylor, Marisa Schwartz; Lieberman, Rebecca (2023-02-02). "How to Forge Shells for Ukraine's Artillery". The New York Times. ISSN   0362-4331 . Retrieved 2023-02-02.