1. Piston anodizing equipment Introduction
With the high power of engine, the thermal stress and mechanical stress of piston increase. Therefore, the cracking phenomenon (hot crack) often occurs around the combustion chamber at the top of piston, which has become an important problem of aluminum alloy piston. In order to solve this problem, our company developed the first piston fast hard anodizing equipment in 1996. The experiment and application show that the hard fast anodizing treatment is very effective to inhibit the thermal cracking of the top of the piston, especially at the mouth of the direct injection combustion chamber. When the temperature of the piston rises due to combustion, the base metal part of the combustion chamber mouth will produce the usual compressive stress, If there is an anodizing layer, tensile stress will be generated in the base metal near the anodizing layer, which can alleviate the compressive stress in the aluminum base metal; The melting point of the anodic oxidation film is up to 2000 ℃, and the thermal conductivity is less than 0.16w/m.k, which can make the combustion chamber on the top of the piston bear instantaneous high temperature and play an adiabatic role, with good heat resistance, insulation and anti-corrosion properties
2. Introduction of rapid anodic oxidation process
the piston hard anodizing equipment adopts fast anodizing process. Traditional piston anodizing uses low current treatment method to prevent a large number of Joule heat generated in the oxidation process, which leads to the damage of oxidation film, so the oxidation time is longer and the production efficiency is lower. The piston rapid anodizing process overcomes the shortcomings of traditional hard anodizing, such as long time, low productivity and inconvenient sealing and insulation. By adopting a special cooling method for the oxidation part and increasing the oxidation current density, the oxidation current gradually decreases along the burn curve (coking curve) in the electrolysis process, which effectively avoids the discovery of burn phenomenon and prevents the dissolution of anodic oxide film, so as to achieve the rapid growth of oxidation film, improve the production efficiency and reduce energy consumption. The thickness of anodized film can reach 90um, the anodizing time is 5-10 minutes, and the Vickers hardness is about hv300.
3. features of fast anodizing equipment for pistons
Hard anodizing equipment for pistons include: PLC power source, refrigeration unit, main oxidation tank, auxiliary tank, working plate, circulation system, conductive system, electric system, etc The pre-treatment and post-treatment equipment and other auxiliary facilities
the piston rapid hard oxidation equipment adopts the fully enclosed design, which belongs to the environmental protection equipment. No acid mist discharge, no ventilation treatment, no corrosion of peripheral equipment
this equipment can oxidize not only the top of the piston, but also the ring groove and ring bank
the product can enter the groove at one time, with fast hanging speed and high production efficiency
high performance power supply and refrigeration equipment are adopted, They are all well-known brands in the industry
automatic control of liquid level and temperature is adopted in the oxidation tank and liquid storage tank
the oxidation process is stored in PLC, which can be quickly transferred out when changing the model