A semiconductor processor was having contamination problems from metal and plastic gears due to intense chemical, thermal and high vacuum conditions. They were considering technical ceramics for chemical resistance, however precision pinion gear teeth must be not only uniform, but strong enough to survive load.
Solution

Based on fine features and point stresses in application of a precision ceramic gear Insaco recommended Yttria blended tetragonal zirconia polycrystal (YTZP) ceramic material for toughness and resistance to chipping. The fine grain and unique crystal orientation actually absorb energy to fight fissure or crack propagation.

AZoM - The A to Z of Materials - Machined hard ceramic gears

Because of many years experience machining sapphire as well as YTZP, Insaco was able to provide both materials. The precision machining required to generate useful gear profiles in sapphire was challenging, but the result allowed our customer to proceed confidently with technical trials. YTZP zirconia, being more robust, may still be the ultimate choice for production, but having the choice to fabricate with either material was the key to successful early trials.