Alumina's advantage over nickel is that it can easily operate at 2,200 degrees Fahrenheit without becoming deformed, a significant improvement over today's metal alloys. It shatters easily. The result of its doing so in a jet engine at 20,000 feet would not be pretty. Dead geese are fired from a cannon at 200 miles per hour into an operating jet engine, to reflect the common tendency of such engines to suck up birds. To be approved, the engine must show no signs of indigestion after consuming this fowl meal.
Birds are a problem.
Since 1994 O'Brien has been trying to figure out how to get alumina to pass the frozen butterball test. Five years ago this would have been a foolish idea, on a par with getting a goose to pass intact through a few sets of spinning turbine blades. The answer, O'Brien hopes, is contained in the bar of alumina he now carefully sets on his desk. The idea, O'Brien says, is to alter a ceramic's customary behavior to increase its fracture resistance. Normally a crack appearing in a ceramic wants to spread all over the brittle material.