Sometimes the smallest thing has the largest impact
Do you know how much wire you can extrude from a cubic meter of copper when you can trust it to be indestructible?1
Indestructible insulating enamel4 + indestructible conductive wire = the perfect transformer/motor/generator.
When was the last time you opened a power supply, motor housing, generator, or anything using inductive windings, and found the transformer/motor/coil burned out. For me, it was last week (literally, it was last week). If you could make both the wire used in the windings and the enamel used to coat the wires indestructible, what you would have is the perfect transformer/motor/generator.
Yeah, but this stuff is expensive
Which is why it would make sense for large items, like turbine-style power generators where the limit to the electricity you're generating is suddenly the mechanical stress limits of the linkages and not the heat-generating characteristics of the coils. Better still, indestructible windings and enamel means you can make the coils incredibly dense — and as coil density increases, so does power output. Your efficiency might actually approach unity. Imagine a wire that is no longer a fuse if too much power is put through it. There is no longer too much power, the limitation is literally the speed electrons can be induced to move through the wire.
And if you expand to power utilization, the applications become … impressive
Miniature motors that can turn the propellers on a submarine? Dock 6. Full-size motors that push submarines at tsunami-creating speeds? Dock 2. Car alternators the size of your thumb? Aisle 14. A Dremel the size of a pencil? Aisle 1. An electric car that actually works climbing the Rockies? The display arrives next week. A residential wind turbine that actually powers an entire house? We have on the roof, you can see it as you enter the building.
The process may be expensive, but the material requirements (in terms of how much you need) drop like a rock when you can trust the wire and enamel to be indestructible. The process of making things indestructible would benefit almost any application at any price. A steam boiler the size of a Buick enjoying such high pressure that it can pull a mile-long train? On display by the front counter.
Disclaimer: at hundreds of millions of dollars per-cubic-meter there it is unlikely that any application is worth it. Unless you can jack the price through the roof, the cost recovery time at that price relegates the material to use (not necessarily power generation) in remote locations (like space) where repair costs even more. A spaceship hull would be worth that price. I frankly can't imagine any power generation/utilization solution that ever would. Not even fusion. The cost of using something less capable would be so much more economical that such a solution would only happen as a test, never a commercial solution. So, a frame challenge concerning the price.
Edit: The OP challenged my disclaimer, and he may have a point, although not for the reasons he suggests. It takes a lot of metal to make one billion-dollar plane. And that metal alone just jumped to billions of dollars. Now we have 3-4 billion-dollar planes, which only national economies can afford, and that means 25% of the planes you could have had without the indestructible hulls and infrastructure. Frankly, most nations wouldn't/couldn't justify the price (there actually are limits to what nations can pay for things. It doesn't seem that way, but there are limits nonetheless).
But...
The average car alternator only requires 0.8165 Kg of copper. With indestructible copper and enamel, it might need 20% of that (0.1633 Kg). That's 54,864 alternators at, say \$200M or \$3,645 above "normal" price — for an alternator that will never burn up. It would mean almost nothing to raise the price of cars by \$4k. People would pay that and move the alternator from car-to-car. One alternator for the rest of their lives. Booyah.
A friend of mine once made a good point: it's easier to sell a million items for \$1 each than it is one item for \$1,000,000. The little things would pay off better than the big things.3
1 A cubic meter of copper weighs 8,930 Kg. 40 Gauge wire weighs 0.04454 grams/meter for 200,490.6 Kilometers of wire. That's enough wire to wrap the equator 5 times.2 And you might be able to use thinner wire than that. It's a lot of honking wire.
2 Of course, the wire is indestructible. If you wrapped the equator just once and tied the two ends to space ships, assuming a reasonable amount of thrust, could you garrote the world in half? It gets the mind wondering, doesn't it?
3 An astute observer might note that making indestructible commodities eventually drives a company out of business. It's the reason antique-anything tends to last longer than the crap we buy today — because there's more money to be made with failure. This is true for power generation, too. The last thing power generating companies want — ever — is a convenient (if expensive) way to run themselves out of business. After all, eventually a class-action lawsuit will point out the fusion power plant has paid itself off and the power rates should drop to rock-bottom. U.S. President Bill Clinton won his campaign for president with the slogan, "it's the economy, stupid." In the end, the OP's indestructibility formula would revolutionize the world — if the inventor could survive to bring the formula to market.
4 The beauty of an indestructible enamel — or any indestructible insulator — is that it won't arc between wires no matter how close the conductors get. Theoretically, an indestructible insulator is a perfect insulator.