| 摘要 |
The invention concerns a method which consists in subjecting a batch of polymetallic parts to a heat cycle comprising at least a phase during which the interface (4) is compressed by differential expansion of the components (2, 3) of the polymetallic parts (1) and a phase during which the contact surfaces (2', 3') of the interface (4) are contacted with an oxidising medium. The compression phase and the contact phase with the oxidising medium can be the same phase. Thus, the protrusions of the contact surfaces (2', 3') are flattened and an oxidised layer is formed on the contact surfaces (2', 3'). The invention is useful is particular for treating polymetallic coins to enable the implementation of more efficient methods for controlling the authenticity of coins.
|
