Apple has applied for patent No.
12/755263 "Nitriding Stainless Steel for Consumer Electronic Products" (
PDF ), which describes a special scratch-resistant coating for metal consumer electronics cases. The coating is planned to be done by
nitriding the top layer of steel.
Apple emphasizes that the layer will be very thin (from 15 microns), so that the consumer will maintain the look and texture of an ordinary steel coating. According to the patent application, on the Vickers scale, the hardness of the coating will be increased to 1000 units (for ordinary steel it is in the range of 150-600). In this case, the material will not interfere with the passage of electromagnetic waves.


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The patent application was published last week, filing date - April 6, 2010 (the inventor is Douglas Weber). Recall that in August of this year,
Apple entered into an exclusive agreement with Liquidmetal Technologies , the developer of amorphous metal alloys with a unique crystal structure.