Automobile circulating pump usually adopts the following materials:

1. Aluminum alloy: Aluminum alloy is a lightweight and corrosion-resistant material, which is often used in the manufacture of automobile circulating pumps. Aluminum alloy has good thermal conductivity and mechanical strength, and can effectively withstand working conditions in high temperature and high pressure environment.

2. Cast iron: Cast iron is a commonly used material with high strength and wear resistance, which is suitable for manufacturing automobile circulating pumps. The material of cast iron is stable, which can withstand high working pressure and temperature, and ensure the stable operation of circulating pump.

3. Stainless steel: Stainless steel has excellent corrosion resistance and high temperature resistance, and is often used in the manufacture of automobile circulating pumps. Stainless steel can resist corrosion and oxidation, keep the circulating pump clean and hygienic, and ensure the normal operation of the circulating system.

4. Plastic: Some parts or housings of automobile circulating pumps are made of plastic materials, such as polypropylene (PP) and polyethylene (PE). Plastic materials have the characteristics of light weight, corrosion resistance and insulation, and are suitable for some low-pressure and low-temperature circulating pump components.

5. Bronze: Bronze is a metal material with high hardness and good wear resistance, which is often used in bearings, impellers and other parts of automobile circulating pumps. Bronze material can improve the wear resistance and stability of circulating pump and prolong its service life.

To sum up, the materials of automobile circulating pump mainly include aluminum alloy, cast iron, stainless steel, plastic and bronze, etc. Choose appropriate materials according to different working conditions and requirements to ensure the stable performance and reliable operation of the circulating pump.