Reply To: turn heat into electricity

[KeithPickering]

Physical strength, rather than dielectric strength, is the key. There are plenty of materials better than alumina from a dielectric standpoint, but you’d have to look long and hard to find anything stronger. And if breakage is the problem, that’s a tough nut to crack. In that regard it would be useful to know for sure the failure mode: flexural, tensile, or compressive. From the description above I’m guessing flexural, as the shots bend the “brim” of the hat (but I could be wrong). Macor, for example, has 3 times the dielectric strength as alumina, but only 1/4 the flexural strength. So if alumina is going to break under the stress, Macor will too.

In spite of asymmetric implosion’s comments, I’m thinking a zirconia ceramic may be the solution. Dynacer (http://www.dynacer.com/data_sheets.htm) has several grades of a zirconia ceramic they call Technox which has 3 to 4 times the flexural strength as alumina. Pure zirconia also beats alumina in dielectric resistance too. And like all ceramics it looks like it can be made into pretty much any shape.