Disclosed is a method for manufacturing a horological component according to which a silicon-based piece having the desired shape of the horological component is produced and the piece is subjected to a thermal oxidation and deoxidation treatment to remove a predetermined thickness of silicon in order to increase the mechanical strength of the piece. This method is characterized in that the thermal oxidation and deoxidation treatment is carried out in several steps, each step including a thermal oxidation phase followed by a deoxidation phase.

A timepiece includes a mechanical oscillator, formed by a balance and a piezoelectric balance spring, and a control device for controlling the frequency of the mechanical oscillator. This control device is arranged to be capable of generating time-separated control pulses, each including a momentary decrease in an electrical resistance applied by the control device between two electrodes of the piezoelectric balance spring relative to a nominal electrical resistance. The control device is arranged to be capable of applying a plurality of control pulses during each time of a series of distinct correction times or without interruption in a continuous time window, in order to respectively synchronize the mechanical oscillator at a correction frequency whose value depends on a detected positive or negative temporal drift or at a desired frequency for the mechanical oscillator.

A process for producing a metal alloy balance wheel by molding includes a) making a mold in the negative shape of the balance wheel; b) obtaining a metal alloy that has a thermal expansion coefficient of less than 25 ppm/° C. and is able to be in an at least partly amorphous state when it is heated to a temperature between its glass transition temperature and its crystallization temperature; c) putting the metal alloy into the mold, the metal alloy being heated to a temperature between its glass transition temperature and its crystallization temperature so as to be hot-molded and to form a balance wheel; d) cooling the metal alloy to obtain a balance wheel made of the metal alloy; and e) releasing the balance wheel obtained in step d) from its mold. The process also includes a step for over-molding flexible centering components in the hub.

A balance wheel including a rim connected to a hub with at least one arm, wherein the balance wheel includes an adjustable auxiliary temperature compensation system mounted in the space defined by the rim to allow adjustable temperature compensation of the balance wheel.

A bimetallic device, the difference in expansion coefficient of which is between 10 and 30 10.sup.−6 K.sup.−1, for providing a resonator with thermal compensation via the balance wheel.

A process for producing a metal alloy balance wheel by molding, the process including the following steps: a) making a mold in the negative shape of the balance wheel, b) getting hold of a metal alloy that has a thermal expansion coefficient of less than 25 ppm/° C. and is able to be in an at least partly amorphous state when it is heated to a temperature between its glass transition temperature and its crystallization temperature, c) putting the metal alloy into the mold, the metal alloy being heated to a temperature between its glass transition temperature and its crystallization temperature so as to be hot-molded and to form a balance wheel, d) cooling the metal alloy to obtain a balance wheel made of the metal alloy, e) releasing the balance wheel obtained in step d) from its mold.

A balance for timepieces includes a rim, a hub, and at least one arm connecting the hub to the rim. At least one portion of the balance is made of an at least partially amorphous metal alloy. The at least partially amorphous metal alloy is based on an element chosen from the group consisting of platinum, zirconium and titanium, and has a coefficient of thermal expansion comprised between 7 ppm/° C. and 12 ppm/° C. The balance can be manufactured by moulding. A resonator can include such a balance and a monocrystalline quartz balance spring.

Some embodiments are directed to adjusting the oscillation frequency of an oscillating system for a watch movement, including: selecting a hairspring, selecting a balance belonging to a predetermined class, without a balance rim, at least two weight elements for balancing in a predetermined batch, pairing the hairspring with the balance and the at least two weight elements, measuring an oscillation frequency of the oscillating system including the hairspring, the balance and the at least two weight elements, and selecting at least one of a balance of another class or of the at least two weight elements of another batch if the measured oscillation frequency does not correspond to a desired oscillation frequency.

A process for producing a metal alloy balance wheel by molding includes a) making a mold in the negative shape of the balance wheel; b) obtaining a metal alloy that has a thermal expansion coefficient of less than 25 ppm/° C. and is able to be in an at least partly amorphous state when it is heated to a temperature between its glass transition temperature and its crystallization temperature; c) putting the metal alloy into the mold, the metal alloy being heated to a temperature between its glass transition temperature and its crystallization temperature so as to be hot-molded and to form a balance wheel; d) cooling the metal alloy to obtain a balance wheel made of the metal alloy; and e) releasing the balance wheel obtained in step d) from its mold. The process also includes a step for over-molding flexible centering components in the hub.

A balance for timepieces includes a rim, a hub, and at least one arm connecting the hub to the rim. At least one portion of the balance is made of an at least partially amorphous metal alloy. The at least partially amorphous metal alloy is based on an element chosen from the group consisting of platinum, zirconium and titanium, and has a coefficient of thermal expansion comprised between 7 ppm/° C. and 12 ppm/° C. The balance can be manufactured by moulding. A resonator can include such a balance and a monocrystalline quartz balance spring.