What are the uses of potassium citrate in electroplating?
Cyanide-free complexing agents commonly used in imitation gold electroplating mainly include pyrophosphate-based potassium pyrophosphate, citrate-based potassium citrate, tartaric acid (salt)-based potassium tartrate, and HEDP. Hydroxyethylidene diphosphonic acid (HEDP) system Potassium pyrophosphate is a complexing agent and has good complexing characteristics, and the electroplating solution prepared using potassium pyrophosphate as a complexing agent has stable quality and a wide range of usable processes. It cannot be electroplated directly on steel substrates, which limits its application range.
Potassium citrate is a complexing agent with strong ignition ability and does not appear when electroplating on copper-iron substrates. Although there is a substitution phenomenon, the quality of the electroplating solution manufactured using potassium citrate as a complexing agent is unstable and the dispersion of the electrolyte is low. Although the complexing ability is high using potassium tartrate as a complexing agent, the plating structure manufactured using potassium tartrate is loose. HEDP has good ignition ability and electrolyte dispersibility as a complexing agent, but the electroplating process range is narrow and its bonding ability with the matrix is poor. poor.
Please tell me why the solder flows at a high temperature of 420 degrees during electroplating.
I don't know much about hardware products. This phenomenon does not occur with tin plating or silver plating. Electroplating with nickel may cause electroplating problems because organic substances are added during the electroplating process. Used to change the crystallization of coatings. Arrangement affects solderability. However, problems with the flux used for welding cannot be ruled out.
What are the hot tin specification requirements?
Wire tin plating approval specifications Public fire protection components must be tinning, which is more important than indoor components. Firefighting is more important than Taishan. The specifications are that the hot tin should be full, shiny, uniform and free from lumps or residue, which means that the tin should not be hot when cold. After ironing, an oily residue will remain on the thread and the edges of the thread, which feels like oil and must be cleaned off. The thread on the edge of the thread should not be burned or blackened, the copper wire should not be exposed, and it should be even and full. The official requirement is that the ends of the wires connected to the junction box must be tinned. This allows the current to integrate and eliminates wire contact surfaces, preventing overcurrents from occurring, heating and burning the device and causing a fire. 1. Hot tin plating is to prevent the copper core cable from splitting and causing accidents. It is convenient to install the cable after ironing the tin. 2. Cable joints are also called cable heads. After laying a cable, the segments must be connected as a whole to create a continuous line, and these connection points are called cable joints. The cable joint in the center of the cable line is called the middle joint, and the cable joints at both ends of the line are called terminal heads. Cable joints are used to lock and secure incoming and outgoing cables and are waterproof, dustproof and anti-vibration. 3. Hot tin: To reduce the contact resistance of the joint and increase the mechanical strength of the joint.
Is there an expert who can tell me about the tin smelting process and process operation technology?
In nature, tin rarely exists in a free state, so pure metallic tin rarely exists. The most important tin ore is cassiterite, whose chemical composition is tin dioxide. Smelting tin is as easy as smelting copper, iron or aluminum, and if you burn cassiterite and charcoal together, the charcoal reduces the tin from the cassiterite. Apparently, when ancient people made bonfires to roast wild animals in areas with tin mines, the cassiterite in the ground would have been reduced by the charcoal, releasing a silvery, molten tin liquid. Because of this, tin was discovered very early.
Currently, about 18 types of tin minerals have been discovered. The most important is called cassiterite, which is currently the main raw material for tin smelting. There is very little pure cassiterite in nature, and most of the common cascades are dark brown-black or brown in color because they contain iron, manganese and other elements. The hardness of cassiterite is relatively high, making it impossible to carve with a knife, and the chemical properties of cassiterite are so stable that they are almost insoluble in any chemical solvent at room temperature and pressure. Therefore, stone can be destroyed by wind, frost, sword, sun, and rain. The appearance remains unchanged.
Cashterite is not tin yet. Cascade must be mined from the ground through the hard work of miners, and after removing the impurities contained in it through various methods, the cassiterite is burned with coke, quartz, and limestone, and the final product becomes metallic tin.