Metal article layered with a nickel-phosphorus alloy and a protective
coating
    2.
    发明授权
    Metal article layered with a nickel-phosphorus alloy and a protective coating 失效
    用镍 - 磷合金层压的金属制品和保护涂层

    公开(公告)号:US4497877A

    公开(公告)日:1985-02-05

    申请号:US491101

    申请日:1983-05-03

    摘要: A metal article which covered with a nickel-phosphorus alloy and which is covered on its outer surface with a protective layer which comprises CrPO.sub.4, Cr(OH).sub.3 and may also comprise Cr.sub.2 (SO.sub.4).sub.3 and in which no nickel is present. The layer provides an excellent corrosion protection. In a particular embodiment the layer is black, scratch-resistant in normal use, cannot be wiped off and is not sensitive to finger prints and is extremely suitable for decorative applications. The layers can be obtained electrolytically in a bath which comprises chromic acid and optionally reversed current in a given frequency range, a given range of current densities and a given range of ratios of cathodic to anodic pulse durations. In order to obtain the black layers the cathodic time duration is only a fraction of black layers the anodic time duration.

    摘要翻译: 覆盖有镍 - 磷合金并且在其外表面上覆盖有包含CrPO 4,Cr(OH)3并且还可以包含Cr 2(SO 4)3并且其中不存在镍的保护层的金属制品。 该层提供了极好的防腐蚀性能。 在一个具体实施方案中,该层是黑色的,在正常使用中是耐刮擦的,不能被擦除并且对指纹不敏感,并且非常适用于装饰性应用。 这些层可以在包含铬酸和在给定频率范围内的给定范围的电流密度的给定范围以及阴极与阳极脉冲持续时间的给定范围的范围内的电镀中电解获得。 为了获得黑色层,阴极持续时间只是黑色层的一部分阳极时间。

    Method of treating objects the surface of which consists of tin
    3.
    发明授权
    Method of treating objects the surface of which consists of tin 失效
    处理其表面由锡构成的物体的方法

    公开(公告)号:US4273625A

    公开(公告)日:1981-06-16

    申请号:US178045

    申请日:1980-08-14

    IPC分类号: C25D9/04 C25D11/00 C25D11/34

    CPC分类号: C25D11/34 C25D9/04

    摘要: Treating objects of which at least the surface consists of tin in order to obtain a satisfactory corrosion resistance. To this end the objects are subjected in a tungstate solution of at least 0.02 M and having a pH of 4-11 alternately to a cathodic and an anodic polarity (so-called periodically reversed current). The frequency with which the current reverses must be between 0.2 and 2 Hz and the current density must be between 0.2 and 1 A/dm.sup.2, the ratio of the anodic to the cathodic density being from 0.5-1.

    摘要翻译: 处理至少表面由锡组成的物体,以获得令人满意的耐腐蚀性。 为此,将物体在至少0.02M的钨酸盐溶液中交替地具有4-11的pH值至阴极和阳极极性(所谓的周期性反转电流)。 电流反转的频率必须在0.2和2Hz之间,电流密度必须在0.2和1A / dm2之间,阳极与阴极密度的比例为0.5-1。