| 摘要 |
The material comprises a base layer, e.g. of silver or white gold, covered with a layer of precious metal and plated with platinum. The platinum coating contains microscopic particles of other materials, selected from the group comprising silicium, tungsten carbide, nitride carbide, diamond and PTFE. The platinum coating is 2.5-3.5 mu m thick, and it can be applied by chemical, physical or electrolytic means.
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