Gold Plating

Black chrome plating refers to coating the surface of a workpiece with a layer of black chrome. The black chrome coating is not pure metallic chrome, but an amorphous oxide crystal. The content of metalliElectroplating with 24K gold involves using pure gold, but the actual gold content is 99.998%. In theory, only 100% gold can be called 24K gold, but in reality, it is not possible to have 100% gold. Therefore, in China, it is regulated that gold with a purity of 99.96% or higher (including 99.96%) can be called 24K gold, also known as “thousand-foot gold.” In society, 24K gold is commonly understood as “thousand-foot gold.”

Applicable electroplating techniques for 24K gold plating include hanging plating, barrel plating, shake plating, continuous plating, and vibratory plating. However, it should be noted that the plating accuracy for 24K gold is relatively poor, and it is often difficult to achieve complete plating inside deep or blind holes.

Film thickness for 24K gold plating refers specifically to the thickness of the gold layer. It generally ranges from 0.5 microns (0.125μm) to 120 microns (3μm). Therefore, it is not uncommon for customers to request gold plating with a thickness of several millimeters. To clarify, such requests indicate that the customer is still unfamiliar with gold plating techniques. (Note: 1 millimeter = 100 microns = 1000 micrometers = 40,000 angstroms. Additionally, angstroms are very close to microinches. So, if a drawing specifies a gold layer thickness of 20 microinches, it can be directly expressed as plating with 20 angstroms of gold.)

Overall film thickness for 24K gold plating varies depending on the material of the workpiece. Different pretreatment methods are required during the gold plating process. For example, in the case of aluminum alloy materials, after zinc plating and nickel underplating, gold plating can be applied directly. However, depending on the requirements of the workpiece’s end use, additional processes such as copper/acidity copper/flash copper plating or strike nickel plating may be necessary. Therefore, for precision components with tolerance requirements, consideration should be given to the residual dimensions due to film thickness before gold plating. Generally, the overall film thickness for 24K gold plating ranges from 1 to over 20 microns.

Wear resistance of 24K gold plating: Gold plating with 24K gold does not mean it is immune to wear. However, compared to pure gold or soft gold, the surface hardness of hard gold plating is higher, resulting in greater wear resistance. The surface hardness of hard gold plating is generally around 120 Vickers hardness.

Cost calculation for 24K gold plating primarily depends on the cost of gold consumed, which accounts for approximately 40-50% of the total cost. This cost is mainly determined by the surface area of the workpiece to be gold-plated and the thickness of the gold layer. Additionally, factors such as the material of the workpiece, its shape, size, the complexity of the plating requirements, and the difficulty level of electroplating, as well as the quantity of workpieces in a batch and whether it is a one-time or long-term order, all significantly impact the quotation. Therefore, electroplating quotations are usually subject to negotiation, with a high degree of subjectivity.c chrome in the coating is only 50%-70%, while the rest is chromium oxide. The black chrome coating has a loose crystalline structure with a branching pattern, which allows it to fully absorb light waves and appear black. It has been proven that black chrome coating is the most excellent selective absorber among all black electroplating and coating as solar energy development continues. The ratio of the absorption rate (a) to the reflection rate (y) of black chrome coating can be greater than 10, making it widely used in solar energy collectors, weapons, optical instruments and cameras. In addition, black is relatively solemn, so it is increasingly used in automotive, daily light industry decorative parts, and other fields.