Tiny particles, huge impact: Nanotechnology to help warfighters

PICATINNY ARSENAL, N.J. — To the ordi­nary per­son, it may seem like noth­ing more than a sim­ple pow­der. To engi­neers here at the Arma­ment Research, Devel­op­ment and Engi­neer­ing Cen­ter, this tiny sub­stance has the poten­tial to do some extra-ordi­nary things for warfight­ers.

From the tanks they dri­ve, to the armor they wear, to the ammu­ni­tions they fire — the “nano” pow­ders devel­oped by ARDEC’s nan­otech­nol­o­gy team can have prac­ti­cal appli­ca­tions in near­ly every part of the Soldier’s inven­to­ry.

“Nano-pow­ders pro­duced by the ARDEC team exhib­it unique chem­i­cal, phys­i­cal and mechan­i­cal prop­er­ties that far exceed the capa­bil­i­ties of con­ven­tion­al mate­ri­als,” said Joseph Paras, mate­ri­als engi­neer.

These improved nano-prop­er­ties include reduced weight, high­er strength, increased dura­bil­i­ty, increased reac­tiv­i­ty, and the abil­i­ty to vary or “tune” cer­tain prop­er­ties. These prop­er­ties allow for great poten­tial when it comes to reduc­ing the weight of Sol­dier equip­ment and improv­ing lethal­i­ty and sur­viv­abil­i­ty.

This cut­ting-edge nan­otech­nol­o­gy has been under way at ARDEC for the last 10 years, and so far has shown sig­nif­i­cant progress. In fact, ARDEC’s nan­otech­nol­o­gy lab is the largest facil­i­ty in North Amer­i­ca to pro­duce nano-scale pow­ders and mate­ri­als.

Nano Warfight­er Appli­ca­tions

Nano-pow­ders can be heat­ed and mold­ed to a vari­ety of shapes and sizes, such as coils or plates, which can be applied to a wide range of prod­ucts like nov­el explo­sives, war­heads and coun­ter­mea­sure flares.

One exam­ple is using nano-mate­ri­als to devel­op nov­el light­weight com­pos­ites that could serve as alter­na­tives to tra­di­tion­al steel.

“The Army uses a lot of steel — and steel is heavy,” Paras said. “There is a big push across the Army and the Depart­ment of Defense to find a lighter alter­na­tive. We’re using nan­otech­nol­o­gy to com­bine alu­minum and oth­er mate­ri­als to enhance the strength, so that it can com­pete with the per­for­mance of steel.”

One such nano-com­pos­ite mate­r­i­al is one-third the weight of steel, which can have a mon­u­men­tal impact if applied to the Army’s tanks and oth­er com­bat vehi­cles.

“It would great­ly reduce fuel costs, as well as ease the bur­den for logis­tics. There are many vari­eties of steel, so we’d have to do the same kind of tai­lor­ing for this mate­r­i­al,” Paras said.

Nano-mate­ri­als can also have prac­ti­cal appli­ca­tions in the Soldier’s armor, as strong bonds formed by the nano-par­ti­cles can great­ly increase mul­ti-hit capa­bil­i­ty.

They also have appli­ca­tions in a vari­ety of ener­get­ics, or explo­sives. “By mak­ing alu­minum on the nano-scale, we change/increase the avail­able sur­face area so it can poten­tial­ly burn spon­ta­neous­ly as soon as it hits the air, mak­ing it more reac­tive,” Paras said. “When using a nano-scale ener­getic, it’s pos­si­ble to increase the yield over tra­di­tion­al explo­sives.”

One suc­cess sto­ry in using nan­otech­nol­o­gy in ener­get­ics is a nano-iron mate­r­i­al that is now being explored as an alter­nate source for use in the M211 flares.

The clos­est of these nano-prod­ucts to be field­ed is “Green Primer” which is essen­tial­ly a lead-free primer for ammu­ni­tion.

“The primer is what sets off the gun pow­der — and though the Army has removed lead from the bul­lets them­selves, there’s still some lead azide in the primer,” said Darold Mar­tin, senior engi­neer at the Par­tic­u­late Mate­ri­als Lab. “The nano-ver­sion of this sub­stance is much safer and much less tox­ic. It could be used in a range of muni­tions.”

Nano break-down

“When we look at mate­ri­als on a nano lev­el, we’re look­ing at ultra­fine par­ti­cles that are on the order of one-bil­lionth of a meter in diam­e­ter,” Paras said. “It gives us tremen­dous abil­i­ty to change the way these mate­ri­als nor­mal­ly work, due to the extra­or­di­nary phe­nom­e­na that hap­pen when you go to the nano scale.”

Nano-struc­tured pow­ders are cre­at­ed when a com­bi­na­tion of mate­ri­als are con­tin­u­ous­ly crushed using a high-ener­gy grind­ing process, called milling.

“We’re basi­cal­ly tak­ing con­ven­tion­al sub­stances like alu­minum or mag­ne­sium, and we’re con­tin­u­ous­ly break­ing them up in the milling machine and reshap­ing them into a very fine, lamel­lar nano-struc­ture,” Paras said. “By reduc­ing the grain size, you can great­ly enhance the prop­er­ties of the met­al.”

In addi­tion to mak­ing nano-com­pos­ite pow­ders, the team can also cre­ate nano-struc­tures from scratch, using an advanced vapor­iz­ing and cool­ing process.

“We take raw alu­minum and melt it using extreme­ly high-tem­per­a­ture plas­ma, so it turns into its vapor state,” Paras said. “Then we “quench” it — which means we cool it down very rapid­ly to con­dense out very tiny par­ti­cles. It’s sim­i­lar to water con­dens­ing on the out­side of a cool glass, except we cool so fast, the vapor instan­ta­neous­ly becomes a sol­id. Then, we can extract the nano-par­ti­cles and har­vest them for use in a wide array of appli­ca­tions.”

Why Nano, Why now?

Many con­sid­er nan­otech­nol­o­gy to be a rel­a­tive­ly new field, emerg­ing in the sci­en­tif­ic com­mu­ni­ty about 20 years ago. How­ev­er, the ear­ly ori­gins of the sci­ence stem back to medieval times, when arti­sans crushed clay par­ti­cles to cre­ate a glit­tery glaze on their pot­tery.

“The the­o­ries behind nano-sci­ence have always been there, but being able to make the mate­ri­als and put them into a use­ful con­fig­u­ra­tion — that kind of tech­nol­o­gy and equip­ment hasn’t been there until recent­ly,” Mar­tin said. “We take the­o­ry from uni­ver­si­ties or small busi­ness­es that do the research, and we tran­si­tion them into promis­ing tech­nolo­gies.”

The ARDEC is at the fore­front of nan­otech­nol­o­gy, even with­in pri­vate indus­try. In fact, Mar­tin not­ed that many indus­try part­ners pro­vide fund­ing to ARDEC to con­tin­ue research in the nano field.

As with any new tech­nol­o­gy, keep­ing the prod­uct at a rea­son­able cost is always a chal­lenge.

“It’s such a new tech­nol­o­gy, so we can’t bring the man­u­fac­tur­ing costs down yet. We have to re-tool our facil­i­ties to be able to mass pro­duce a lot of this stuff,” Mar­tin said.

“If it was easy, it would be done already,” he added. “It’s sort of like bak­ing, in that there is an art to it, you can’t always tell why cer­tain things work exact­ly right togeth­er, but when they do, you know it.”

So while ARDEC sci­en­tists con­tin­ue to devel­op new nano-pow­ders and mate­ri­als, while find­ing cost-effec­tive ways to car­ry them for­ward, the long-term goal is to bring more capa­bil­i­ty to the warfight­er.

“We’re work­ing on emerg­ing tech­nol­o­gy that is basi­cal­ly try­ing to enhance the lethal­i­ty in the hand of the Sol­dier and the sur­viv­abil­i­ty of the Sol­dier,” said Deep­ak Kapoor, nano-mate­ri­als team lead.

“If you can pro­vide him bet­ter per­form­ing mate­ri­als that can help him live longer, sur­vive longer, and kill longer — that is what any new tech­nol­o­gy is try­ing to cap­ture right now.”

Source:
Unit­ed States Army

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