The manufacturing process involves a number or stages shown schematically in figures 1 to 12. The first step is to weigh, dry mix and ball mill [2] the raw materials. The uniform mixture is when heat treated (calcined) [3], during which the components react to form the polycrystalline phase. The calcined powder is spray dried [5] to add binder in order to increase it's reactivity and to improve pressing properties.
After shaping by dry-pressing [6], the binder is burnt out [7] by slowly heating the green ceramics to around 700oC. The parts are transferred to another furnace, where they are sintered [8] between 1200 and 1300oC. The dimensional tolerance of fired parts (± 3%) is improved by cutting, grinding, lapping etc. [9].
Electrodes are applied either by screen printing or chemical plating or vacuum deposition [10]. Poling then is carried out by heating in an oil bath at 130-220oC, and applying an electrical field of 2-8 kV/mm to align the domains in the material [11]. The oil bath is used a heat source and to prevent flash over.
Final inspection [12] is performed 24 hours later, and includes testing of electrode-ceramic bonding as well as measurement of dimensional tolerances, dielectric and piezoelectric properties.
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| [1] Raw Materials | [2] Mixing | [3] Calcining | [4] Milling |
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| [5] Spray Drying | [6] Pressing | [7] Binder Burnout | [8] Sintering |
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| [9] Grinding/ Polishing | [10] Electroding | [11] Poling | [12] Final Inspection |
