Flying Disk Materials

Single crystal materials are phenomenally strong. Single crystal steel blades are used in aircraft turbines. They are expensive to produce, but the process is relatively simple. The metal is placed in a mold which has a spiral or helix (pigtail) at the bottom. The mold is cooled beginning at the base of the helix and crystals form randomly. As the crystals propagate up the helix, only those with the correct orientation continue to propagate until one successful crystal orientation makes it to the actual mold where it grows into a single crystal turbine blade. The blades are tested for crystal orientation using X-ray diffraction, and flawed or incorrectly oriented crystals are discarded. The process is time-consuming and expensive, but worthwhile because the resulting blades are much stronger and maintain their strength at high temperatures. How much stronger are the blades?

                          Theoretical Strength  Bulk Strength
                                                 (typical)
                          ____________________  _____________
   Material                 psi       MPa       psi      MPa
_________________________________________________________________
Iron ( carbon steel )     2,000,000  13,800    100,000  690
Copper                    2,000,000  13,800     70,000  483
Glass                     1,200,000   8,280     60,000  414
Graphite                  4,000,000  27,600     20,000  138
Alumina                   5,200,000  35,880     80,000  552
_________________________________________________________________

Clearly, the theoretical strengths of materials are at least an order of magnitude (10x) higher than current materials.

How would a material which is light, thin as a sheet of tin, but can take a blow from a sledgehammer be produced? Perhaps crystalline tungsten or titanium. (You may have heard of titanium, light as aluminum, strong as steel. It makes great bike frames, if you have $$.)

Since single crystals don't have defects, they do not exhibit plastic deformation as readily as ordinary materials. In ordinary materials, defects move through the material structure so that a crumpled piece of aluminum foil remains crumpled, a copper wire remains bent, etc... A defect-free single crystal titanium foil, in addition to being very strong, would also refuse to remain crumpled.

Large single crystal objects and sheets would probably need to be grown in micro-gravity.

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