With the rapid development of automobile industry, electroplating technique is widely used on auto parts. In decorative plating, there are plastic plating process and aluminum wheels plating process; in functional plating, there are electroless nickel plating, zinc plating, hard chromium plating, etc.
1. Plastics Plating
Compared with metals, plastics have advantages of low price, light weight and flexible shaping, etc. On the way to seeking energy conservation and environment protection and being luxury and gorgeous, plastics plating process has played an important role in decorative protection process of automobiles. Plastics plating process is widely used in auto parts plating no matter inside or outside the car, such as the logo, door handle, bumper, wheel house, etc.
2. Aluminum Alloy Wheel Electroplating
Aluminum alloy wheel electroplating process originated in America. Because of the perfect combination of the light aluminum alloy and the decorative chromium, the luxury cars present gorgeous and unique assisting with the aluminum alloy wheels. However, the plating on casting aluminum is different from that on steel base. Each process and technical parameter need to be studied and tested seriously, starting from pre-treatment and pre-plating to the real copper plating, nickel plating or chromium plating.
3. Electroless Nickel Plating
Electroless nickel process, with a uniform layer, can be used in auto industry for plating a protective layer of nickel on some complicated auto parts, like wheel gears, radiators and injectors. The aluminum radiators can have good solderability after depositing a 10um layer of nickel. After electroless nickel process the dimension error of gears can be easily kept in the range of ±0.3～0.5um, which needs further machining if electroplating is adopted. When the electroless nickel process is used for plating on oil injector, the nickel layer can offer good ability of anti-fuel corrosion and abrasion. Normally, fuel corrosion and abrasion can lead to the widening of the oil jet hole and the high oil consumption, making the delivery of horsepower beyond standard and speeding the damage of engines. Thus the electroless nickel layer can effectively prevent fuel corrosion and abrasion to increase the reliability and operation life of engines.
Zinc plating and passivation is most commonly used in the protection coating for the auto parts. The steel base and the zinc deposit will form a galvanic cell potential difference, and corrosion-resistance can be improved after passivation, which can prolong the life span of automobile.
5.Hard chromium plating
Piston, piston ring and connecting rod are three main moving parts of the automobile engine, of which the working environment is so harsh that they must be heat-resistant, wear-resistant, corrosion-resistant and withstand changing loading etc. With excellent performance on hardness, anti-corrosion, and anti-friction etc., chromium plating therefore is becoming more and more popular in protection coating for auto engines.
As a pillar industry of national economy, automotive industry plays a key role in developing economy and improving people's life. Now automobile is not just a vehicle for transportation, it also penetrates into people’s life, for people nowadays do not only focus on its dynamic performance and reliability but also its comfort and decoration.
As an important method to improve dynamic performance, enhance outer decoration performance and extend life span of automotive, the rapid development of automotive technology requests a stricter quality standard to the plating technology. Hence, the latest plating technology and techniques can be found in the plating of auto parts.