What Materials and Surface Treatments Are Used for Automotive Parts?

Automotive parts are essential components of a car, including the engine, chassis, body, and electrical equipment. The materials and surface treatment methods of these parts directly and indirectly affect the performance and lifespan of the vehicle.

  1. Main Materials for Automotive Parts

   A. Metal Materials

Metal materials are the most commonly used materials for automotive parts. Key types include steel, cast iron, copper alloys, aluminum alloys, and magnesium alloys.

-Steel is favored for its high strength, good corrosion resistance, and low cost. It is widely used in parts like the car body, fenders, chassis, and engine components.

-Aluminum Alloys and Magnesium Alloys are lighter, corrosion-resistant, and have good thermal conductivity. They are mainly used for the car body, wheels, and engine components to reduce the vehicle's weight.

-Copper Alloys offer good corrosion resistance and wear properties and are generally used in parts like radiators.

B. Non-Metal Materials

Non-metal materials include plastics, rubber, ceramics, glass, and textiles.

1. Plastics: Plastics are lightweight, easy to process, and cost-effective. Commonly used plastics like ABS, PC, PP, and PE are found in interior components, dashboards, and electrical parts. These materials not only reduce weight but also help lower noise and vibrations. Specialized high-temperature and wear-resistant plastics are used for engine oil pans, turbine blades, and other components.

2. Rubber: Rubber is widely used in automotive parts due to its high elasticity, wear resistance, good plasticity, and sealing properties. It effectively dampens vibrations and noise during driving. Common rubber components include tires, seals, and shock absorbers.

3. Glass: There are various types of automotive glass, such as windshield glass, side window glass, and rearview mirror glass. Glass offers good visibility and hardness, providing a clear view for passengers. Special types of glass with functions like heat insulation, soundproofing, and anti-pinch are used throughout the car.

4. Ceramics: Ceramics have high hardness, excellent wear resistance, and chemical stability. They are used in engine components, braking systems, and other parts.

5. Textiles: Textiles are used in smaller quantities for components like seats and door panels. They offer good water resistance and softness, meeting comfort needs for vehicle occupants.

In the CNC machining industry, materials for automotive parts mainly include stainless steel, aluminum and aluminum alloys, and plastics. These materials often require various surface treatment methods.

2. Surface Treatment Methods for Automotive Parts

A. Coating

Coating is one of the most common surface treatment methods for automotive parts. It offers corrosion resistance, aesthetic appeal, and improved surface hardness. The process includes pre-treatment of the part's surface—such as oil removal, rust removal, and phosphatization—followed by painting or coating. Common coating materials include silicon, tungsten, and titanium.

B. Oxidation

Oxidation treatment involves forming an oxide layer on the surface of automotive parts through an oxidation reaction to enhance corrosion resistance and appearance. The main methods are anodic oxidation and cathodic oxidation.

C. Electroplating

Electroplating forms a metal coating on the surface of a part to improve its corrosion resistance, appearance, and hardness. The process includes pre-treatment, electroplating, and finishing. Electroplating methods include chrome plating, nickel plating, and zinc plating, with the choice depending on customer requirements.

D. Shot Peening

Shot peening uses high-speed air flow to propel shot pellets onto the part's surface, creating a strengthened layer. This method improves surface hardness and fatigue resistance. The effectiveness of shot peening depends on the pellet material and impact speed.

E. Laser Treatment

Laser treatment uses high-energy laser beams for rapid heating or cooling of the part's surface. It improves surface hardness, wear resistance, and fatigue resistance. The treatment effectiveness depends on the laser power and scanning speed.

F. Acid Pickling 

Acid pickling involves immersing and stirring parts in acids like hydrochloric acid, sulfuric acid, or phosphoric acid to remove oxides and impurities from the surface.

G. Plasma Treatment

Plasma surface treatment is used in various processes, such as pre-treatment for coatings and electroplating.

In summary, the choice of materials and surface treatment methods for automotive parts is crucial for the vehicle's performance and longevity. Different materials and treatments should be selected based on the specific application and performance requirements of the parts.

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