The color on the surface of the metal jewelry piece is the natural color. However, sometimes it is necessary to change the color of its surface in order to achieve special effects. For example, 18K gold jewelry is required to be as golden as pure gold, while 18K white gold jewelry (white gold) is required to be pure white like platinum. This requires surface treatment of metal jewelry, so surface treatment manufacturers must use it The vacuum coating machine is used to change the appearance of the workpiece through vacuum ion physical vapor deposition.

         Vacuum coating machine coating is a more complicated process. It not only protects the metal surface of jewelry, but also makes the surface of metal jewelry more beautiful. Metal jewelry coating is divided into natural color coating and heterochromatic coating. Natural color coating means that the color of the coating is the same as the color of the jewelry metal substrate, and the chemical composition of the jewelry metal substrate and the coating are basically the same. For example, 18K gold jewelry is plated with 18K gold, and 14K gold jewelry is plated with 14K gold. Different color coating means that the color and composition of the coating are different from the color and composition of the jewelry metal substrate. For example, 18K gold jewelry is plated with 24K gold or white rhodium.
        Coating is a process of depositing a coating with a desired shape by electrolysis. The basic process of electroplating (taking gold plating as an example) is to immerse the material to be plated in a solution of metal salt (such as potassium gold cyanide) as the cathode. The metal gold plate is used as the anode. After the DC power supply is turned on, a metal gold plating layer will be deposited on the material to be plated.
        Plating is a process of depositing a coating with a desired shape by electrolysis. The basic process of coating (taking gold plating as an example) is to immerse the material to be plated in a solution of metal salt (such as potassium gold cyanide) as the cathode. The metal gold plate is used as the anode. After the DC power supply is turned on, a metal gold plating layer will be deposited on the material to be plated.
       The basic quality requirements for the coating layer:
       1. It is firmly bonded to the base metal and has good adhesion.
       2. The coating is complete, the crystallization is fine and compact, and the porosity is small.
       3. It has good physical, chemical and mechanical properties.
       4. Ken has a coating thickness that meets the standard requirements, and the coating distribution must be even.
       Before metal jewellery is coated with a vacuum coating machine, due to various processing and treatments, it will inevitably adhere to a layer of oil stains and oxide layers generated on the surface, and these oil stains and oxides will affect the quality of the coating. In order to ensure that a coating that meets the electroplating quality can be plated, the dirt and oxide on the surface of the jewelry must be cleaned. There is also a jewelry metal mold after polishing, the surface is rough and not refined enough. It is difficult to plate a strong and anti-corrosive coating on the surface of this material. Even if the coating is barely plated, it will take a short time. The coating on the inner jewelry will peel off, bubbling, pitting, variegation and other undesirable phenomena. Therefore, each process in the early stage of vacuum coating machine coating should be fine.