Test pieces were struck in 2011 and 2013 in the following combinations using newer Martha Washingon dies than found on J2182 combined with a reverse similar in style to regular issue nickels. They have mottos with reversed or scrambled lettering, etc.
Additional information on this can be found in the "ALTERNATIVE METALS STUDY" submitted to the U.S. Mint by Concurrent Technologies Corporation.
Tests were also done for cents and quarters as well.
Examples were struck in the following combinations:
1) Current copper nickel
2) Dura-White-Plated Zinc 3ž Sn (Jarden Zinc Products)
3) Multi-Ply-Plated Steel (Lot #137) (Royal Canadian Mint)
4) Multi-Ply-Plated Steel (Lot #170) (Royal Canadian Mint)
5) 302 Stainless Steel (Carpenter Technology)
6) 430 Stainless Steel
7) G6 Mod (65Cu-22Zn-10Ni-2Mn) (Olin Brass)
8) 669z (75Cu-10Zn-5Ni-10Mn) (PMX Industries)
9) Nickel Plated 31157 (Jarden Zinc Products)
10) Unplated 31157 (62Cu-31Zn-0.5Ni-6.5Mn) (Jarden Zinc Products)
11) Nickel-Plated Steel (aRMourô 25 žm Ni on low-carbon steel) (Royal Mint)
The report has images, usually of one side, for all of these combinations. Click on the thumbnail image to see a couple of these. The alloys used have either a steel or a yellowish color.
According to a February 10, 2014 article by Paul Gilkes in Coin World, the Mint has also experimented with using current copper-plated zinc planchets similar to that used on the current Lincoln cent as imaged below.
"The experimental copper-plated zinc strikes the Mint has executed at the Philadelphia Mint for the 5-cent coin weigh 4.06 grams and maintain the coinís current diameter, according to U.S. Mint officials.
U.S. Mint spokesman Michael White said Jan. 23 that the copper-plated zinc planchets for the 5-cent experimental strikes were supplied by Jarden Zinc Products of Greeneville, Tenn.
Jarden is currently the U.S. Mintís lone vendor for ready-to-strike copper-plated zinc planchets for Lincoln cents.""
It is unclear whether or not, the Mint would confiscate these should any turn up in collector's hands.
Photos courtesy of the U.S. Mint.