Why are precision parts blackened after processing copper materials? How to deal with it?

by:NJPE     2020-01-22
Since ancient times, copper has been used as the main raw material for industrial processing products. It has been processed into various complex-shaped punching products, hardware, military parts products, shells, etc. , and has a wide range of daily uses, such as drainage pipes, medals, electrical parts, musical instruments, valves and pipe fittings in daily life. Why does copper material processed by precision parts turn black? Because copper is an active metal atom, it is prone to chemical reaction when exposed to oxygen in the air. Most of the metal will turn black after oxidation to generate copper oxide. The chemical reaction formula is: 2cu o2 = 2cuo many times, brass parts processed by precision parts are often oxidized and blackened before they are sent to customers, resulting in reduced quality, beautiful appearance, even rework and increased cost. How to deal with it? At this time, passivation should be done. The principle is to attach the upper layer of chemical conversion film. Because it is a chemical conversion film, it cannot be touched by hand. It does not affect conductivity, hardness such as weldability and workpiece size will not change. The treatment process is as follows: put the passivation solution in a stainless steel container, soak the workpiece to be treated for about 5 minutes, take out the workpiece and rinse it with water to dry it; Note that before passivation, the workpiece must be pre-treated in order to prevent oil stains or oxides on the surface of the workpiece. It is necessary to remove oil or clean and oxidize. Cleaning agents or degreasing agents can be used to remove stains, then clean the surface to carry out passivation protection. In order to increase the brightness of the parts, the surface can also be polished with polishing agent before treatment. The polishing process does not require any equipment in the whole process, and direct soaking method can be adopted. Nanjing Precision Engineering Co. , Ltd focuses on: CNC finishing supporting services for automation, aviation, basic scientific research, optical fiber, communication, semiconductor, electronics, medical devices, auto parts suspension and other equipment accessories. Processed Materials: aluminum alloy, stainless steel, magnesium alloy, titanium alloy, nickel-based alloy (invar, kovar) , High-temperature alloy, tungsten-copper alloy, engineering plastics and other special difficult-to-process materials. Processed Products: precision mechanical parts, medical precision parts, aviation parts, instrument parts, optical fiber communication parts, electronic products parts, auto parts, shock absorbers, suspension parts, non-standard components, connectors, alloy parts, hardware shells high-standard products in industries such as radiators. The management personnel are the elites who are familiar with ISO9001 standard and specification. Combining ERP system and bar code management, part of the quality control process adopts Internet of Things technology to ensure the quality of products and the authenticity, real-time and traceability of data, prompt delivery; At the same time, it is in line with international advanced technology and standard testing methods, and has truly achieved Asian prices and American technical standards to ensure high quality; We have more than 20 years of experience in CNC batch processing of various non-standard high-precision parts; We sincerely welcome customers and friends from all walks of life to contact us for inquiries and drawings and samples. Contact hotline: 400-0769382.
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