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. 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. The new explosive will cost $8 per pound, compared to $6 per pound for TNT. As of 2023, IMX-101 filled shells are being used in the 2022 Russian invasion of Ukraine.
Time Magazine called IMX-101 one of the "50 best inventions of 2010".
Composition
IMX-101 is composed of 2,4-dinitroanisole (DNAN), nitrotriazolone (NTO), and nitroguanidine (NQ). The nominal composition is 43.5 wt% DNAN, 36.8 wt% NQ, and 19.7 wt% NTO. Trace amounts of N-methyl-p-nitroaniline (MNA) are included in some formulations to aid in processing. 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.
| Formulation | Key Ingredients | Replaces | Purpose | Qualification Status (2012) |
|---|---|---|---|---|
| IMX-101 | DNAN + NTO + NQ | TNT | Artillery and other large caliber munitions | Material qualified; Type qualified for 155mm M795, on-going for 155mm M1122 and 105mm projectiles |
| IMX-104 | DNAN + NTO + RDX | Comp B | Mortar applications | Material qualified; Type qualification on-going for 81mm mortar, 60mm & 120mm to follow |
| PAX-48 | DNAN + NTO + HMX | Comp B | Mortar and tank ammunition | Material qualified; Type qualification achieved for 120mm IM HE-T tracer round (NAMMO) |
| OSX-12 | DNAN + NTO + RDX + Al | PAX-28 | High blast applications | Material under evaluation |
| PAX-21 Picatinny arsenal explosive | DNAN + RDX + AP + MNA (N-methyl-p-nitroaniline) | Main fill for the 60mm M768 Mortar Rounds | Currently in-use in theater | |
| PAX-41 | DNAN + RDX + MNA | Main fill for the Spider Grenade, thus a low critical diameter is required. |
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. OSX-12 is being studied as a replacement to PAX-28.
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.
See also
- M107 projectile
- XM1128 projectile
Further reading
- The Characterization of IM Explosive Candidates for TNT Replacement
- Explosive Ingredients and Compositions for the IM M795 Artillery
References
- "BAE IMX-101 Explosive Approved To Replace TNT In US Army Artillery". Archived from the original on 2010-08-07. Retrieved 2010-08-03.
- DTIC Background and Introduction to IMX-101, -102 and -103 Archived 2010-08-15 at the Wayback Machine
- The Application of New IM Explosive Candidates - DTIC Online Archived 2012-10-03 at the Wayback Machine
- "Army Approves Safer Explosive To Replace TNT". Archived from the original on 2010-08-20. Retrieved 2010-08-17.
- ^ 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.
- ^ Mark Thompson (2010-11-13). "Less Dangerous Explosives". Time Magazine. Archived from the original on 2013-05-25. Retrieved 2013-06-16.
- 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.
- 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.
- ^ 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.
- 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.
- 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.
- ^ "Insenstive High Explosives (IHE)". Archived from the original on 2014-07-08. Retrieved 2014-06-04.
- "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.
- "DEVELOPMENT & OPTIMIZATION OF A PRODUCTION METHOD FOR MANUFACTURING PAX-41" (PDF). Archived from the original (PDF) on July 19, 2013.
- "IMX-104 High Explosive (HE) Loading of 81mm & 120mm Mortars" (PDF). Archived from the original (PDF) on 2014-06-04.
- 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.