Andrew Derek Turner,James Merotra,David Richard Lewis,Jonathan Speed,James Shawcross
申请号：
US15574357
公开号：
US20180133370A1
申请日:
2016.05.13
申请国别(地区):
US
年份:
2018
代理人:
摘要：
Metal objects are treated by anodising the metal object in contact with an aqueous electrolyte, and then subjecting the anodised metal object to a reversed voltage. The anodising is performed in two stages, firstly to passivate with the formation of an oxide layer, and secondly to form regions in the oxide layer having a higher oxygen to metal atom ratio, for example pits or caps, in this oxide layer. The second stage of anodising is performed by applying a multiplicity of voltage cycles, each voltage cycle involving ramping the voltage between a lower threshold voltage and an upper threshold voltage, and then returning to the lower threshold voltage. The reversed voltage step forms a hydrous metal oxide in the regions of higher oxygen to metal atom ratio, and the oxide layer and hydrous metal oxide together constitute a surface layer which is integral with the metal object, and has ion exchange capacity. After the reversed voltage step the metal object is then contacted with a bio-effective material such as a biocidal metal, which is absorbed into the surface of the metal object. The processing time may be reduced by applying the multiple voltage cycles. The invention also provides a treated metal object which can be prepared by treating a metal object having a micro-rough surface according to the method described above.
