Precious metal plating
Commonly called precious metals are gold, silver, platinum, rhodium, palladium, etc., all of which have low ionization tendency and are chemically stable.
It has excellent corrosion resistance and heat resistance, and there is little change in appearance. The utility value of precious metal plating was limited to decoration and crafts in the old days, but since the time of World War II, the excellent physical and chemical properties peculiar to precious metals have attracted attention, and industrial use has rapidly increased. Today, it is used in the fields of electronics such as computers, communications, measurement, and control equipment, and is indispensable for parts and circuits that place particular importance on reliability.
What is precious metal plating?
Precious metal plating is used in various fields, and is widely used in aircraft, missiles, space equipment, electronic power industry, and home appliances (televisions, audios, video recorders, etc.).
Precious metal plating tends to be thin or partial plating to reduce the plating range as long as the reliability of the function required for its characteristics is not lost.
In addition, silver plating, which is easily discolored among precious metals, is thickened for the purpose of replacing gold plating.
Palladium, which was previously cheaper than gold and rhodium, has been attracting attention as a substitute for gold and rhodium and has been expanding its applications, but it is being reviewed due to the recent rise in palladium (as of December 2019).
Precious metal plating generally has excellent corrosion resistance, so unless there are pinholes or cracks that cause corrosion, almost no corrosion will occur.
For example, if there are pinholes in the noble metal plating on brass, zinc, which is a component of the brass substrate, will be selectively corroded in salt water, and zinc chloride, zinc oxide, zinc hydroxide, etc. will be detected.
In addition, corrosion products such as copper sulfide and copper oxide are detected around pinholes in ammonium polysulfide solution.
If there are pinholes or cracks in the plating film even after applying precious metal plating with good corrosion resistance, local corrosion will be induced, resulting in accelerated corrosion.
Therefore, in precious metal plating, it is especially important to completely cover the material with a plating film, and the structure, surface condition, pretreatment, selection of base plating, etc. of the plating base are also important, and quality control including these is necessary.
Connection Co., Ltd.
Please feel free to contact us for plating, coating, polishing, heat treatment, etc.
Consultations and quotations are free.
4-202-5 Shizugaoka, Fukui City, Fukui Prefecture 910-3635 (Japan)