[0069] The main body 54 may be formed from a variety of extrudable materials or material combinations including but not limited to metals, metal alloys, plastics, ceramics and/or the like. By way of example, the metals may correspond to aluminum, titanium, steel, copper, etc., the plastic materials may correspond to polycarbonate, ABS, nylon, etc, and the ceramic materials may correspond to alumina, zirconia, etc. Zirconia may for example correspond to zirconia oxide.
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0134] The base material of zirconia is zirconium oxide. Zirconia may also include a variety of other components as for example yttrium oxide, chromium oxide, aluminum oxide, hafnium oxide, and/or the like. In one example, the composition of black zirconia comprises greater than or equal to 89% ZrO.sub.2 (zirconium oxide), less than or equal to 7% Y.sub.2O.sub.3 (yttrium oxide), less than or equal to 3% Cr.sub.2O.sub.3 (chromium oxide), and less than or equal to 3% Al.sub.2O.sub.3 (aluminum oxide). In another example, the composition of white zirconia comprises greater than or equal to 93% ZrO.sub.2 (zirconium oxide), less than or equal to 7% Y.sub.2O.sub.3 (yttrium oxide), and less than or equal to 1% Al.sub.2O.sub.3 (aluminum oxide). In each of these examples, the composition may also include 1-2% Hf0.sub.2 (hafnium oxide).
