Apart from a sophisticated mechanism, the material chosen is also crucial. Technical ceramics, as the kind used in watch movements are known, are lighter and harder than steel and extremely resilient. IWC can look back on almost 30 years’ experience in working these materials. As in the manufacture of watch cases many years ago, the company has assumed a leading role in the industry in the use of ceramics for movement components.
The manufacture of very small ceramic parts within the prescribed tolerances, however, is extremely demanding because the basic raw material in powder form shrinks by around a third during the sintering stage. Only very few specialists master the highly complex manufacturing process. On top of this, design or geometrical modifications are usually needed in order to produce a brass or steel component in the high-tech material.
In view of the stresses and strains that affect it, the Pellaton winding system was a candidate for the use of ceramic from an early stage. IWC succeeded in producing the 51900 calibre – the driving force in the Portugieser Tourbillon Mystère Rétrograde – in zirconium oxide rather than copper beryllium for the first time in 2009. This improvement alone played a major role in reducing wear and tear. It seemed obvious that the next step should be to manufacture the winding wheel in this material. However, initial attempts failed: when the steel pinion was press-fitted, the ceramic wheel regularly shattered. The breakthrough came only after a new design and progress in the manufacturing technology. Now, for the 52000-calibre family, the automatic wheel and the pinion are produced together as a single, integrated component in black ceramic. “As a result, the interaction between the pawls and the wheel is now virtually wear-and-tear-free,” says Gäumann.