The difference between tin plating, nickel plating and silver plating for copper bars
1. The purpose of tin plating, silver plating and nickel plating
1) The purpose of copper tin plating: to effectively prevent copper from becoming patina due to moisture, and also to prevent copper from becoming black due to oxidation/sulfidation and affecting electrical contact. After tin plating, the service life of copper is extended several times or even more than ten times, which greatly improves the service life of copper and plays a considerable role in the protection of copper.
2) The purpose of silver plating on copper: to improve conductive contact resistance and enhance signal transmission. (Silver has the best performance, is easily oxidized, and also conducts electricity after oxidation).
3) The purpose of nickel plating on copper: for base or appearance, to improve corrosion resistance and wear resistance. (Among them, chemical nickel has more wear resistance than chromium plating in modern processes).
2. Comparison of tin plating, silver plating and nickel plating
1) Hardness: Nickel is harder than tin and has stronger scratch resistance.
2) Soldering performance: Tin is better than nickel and easier to solder.
3) Anti-corrosion: They are all relatively good and stable in the atmosphere. It's just that nickel's performance in dilute sulfuric acid is far worse than tin's corrosion resistance.
4) Weather resistance: Tin is better than nickel.
5) Decoration: Nickel is bright and scratch-resistant and is mostly used for decorative plating of small hardware, while tin is mostly used for electronic hardware products in welding.
6) The conductivity of tin and nickel is lower than that of copper, with little difference. If you want to think about it, consider that nickel is magnetic and tin is non-magnetic.
3.Plating
From the appearance, it can be seen that the tin-plated products are brighter and silver-white. The nickel-plated products are darker and darker to improve the wear resistance. Thick hard chromium can be plated to improve the conductivity. Silver plating can improve solderability and can be plated with tin or lead-tin alloy.
The difference in performance between tin plating, nickel plating and chromium plating on the copper surface: the hardness of the plating is chromium plating > nickel plating > tin plating; the appearance brightness (for a long time) is chrome plating > nickel plating > tin plating; the chemical stability is nickel plating > chromium plating >Tin plating.
The nickel plating layer has high hardness and good chemical stability, so it is generally used for coating lead materials of electronic devices;
The tin plating layer is soft and easily damaged, but has good solderability, so it is often used as a coating for the soldering ends of electronic device leads.
The purpose is not only to facilitate subsequent plating of other metals, but also to have relatively strong adhesion and wear resistance. Depending on the use occasion, choose nickel plating or tin plating. If it is an exterior component, nickel plating is generally chosen because it looks good and does not discolor after high-temperature testing.
