摘要 |
In a process for anodising a metal object (12), the metal object (12) is contacted with an anodising electrolyte (32), and is first pre-anodised so as to grow a thin oxide film on the surface. The microscopic surface area is then deduced from electrical measurements either during pre-anodising or on the pre-anodised surface. The metal object (12) can then be anodised. This is applicable when treating an implant to provide a surface that has the ability to incorporate biocidal material such as silver ions. The pre-anodising uses a low voltage, for example no more than 2. V, and may take less than 120 seconds. |