Aluminum alloys are widely used in the automotive industry as a typical lightweight metal，Automotive aluminum alloy parts mainly include pistons, cylinder heads, clutch housings, oil pans, bumpers, heat exchangers, brackets, wheels, body panels and decorative parts.
Replacing the traditional steel structure with an aluminum alloy structure can reduce the weight of the car by 30% to 40%, the engine can be reduced by 30%, and the wheels can be reduced by 50%.
The use of aluminum alloys is one of the important ways to reduce the weight of automobiles, protect the environment, save energy, increase speed and transport efficiency. Therefore, it is very necessary to research and develop aluminum alloy automobiles.
The main advantages of aluminum alloys are light weight and good heat dissipation.
1. Application of cast aluminum alloy
Cast aluminum alloys have excellent casting properties. Appropriate alloys and suitable casting methods can be selected according to the requirements and economic benefits of various aspects such as the purpose of use, part shape, dimensional accuracy, quantity, quality standards, mechanical properties, etc.
Cast aluminum alloys are mainly used for:
Casting engine cylinder block, clutch housing, rear axle housing, steering gear housing, transmission, valve train, oil pump, water pump, rocker arm cover, wheel, engine frame, brake caliper, oil cylinder and brake disc, etc. member.
1. Aluminum alloy for engine: Aluminum alloys for automobile engines are the most lightweight, and generally can reduce weight by more than 30%. In addition, the cylinder block and cylinder head of the engine require materials with good thermal conductivity and strong corrosion resistance.
2. Aluminum alloy for wheel hub: Aluminum wheels have gradually replaced steel wheels because of their light weight, good heat dissipation and good appearance. In the past 10 years, the global aluminum alloy automotive wheel has grown at an annual growth rate of 7.6%
3. Application of deformed aluminum alloy: Deformed aluminum alloys are mainly used in the manufacture of doors, trunks and other body panels, bumpers, engine covers, wheel spokes, hubcaps, wheel exterior covers, brake assembly protective covers, muffler covers, anti-lock brakes Brake systems, heat exchangers, body frames, seats, floor panels and other structural parts, as well as decorative parts such as dashboards.
- 3.1. Aluminum alloy for body panels: The application proportion of plates in cars is increasing. For example, 6000 series (AI-Mg-Si series) aluminum alloy plates that have undergone heat treatment (such as: T4, T6, T8) can well meet the requirements of automobiles for shells.
- 3.2. Other aluminum alloy structural parts: Aluminum alloys are also widely used in other parts of the car, such as: General Motors of the United States uses 7021 aluminum plate to make Smure car bumper reinforcement brackets, and Ford uses 7021 aluminum plate to make LincolnTown car bumper reinforcement brackets.
2. Application of new aluminum alloy in automobile
1. Rapid solidification aluminum alloy: Under the condition of rapid solidification (cooling rate up to 104～109℃/S), the material will cause some new features in the structure: ultra-fine microstructure; increase the solid solubility limit of the alloy; highly uniform composition, less segregation or no segregation; formation of new metastable equals.
2. Aluminum matrix composite material: Using ceramic fibers, whiskers, particles, etc. as reinforcing materials to produce aluminum matrix composite materials, its specific strength, specific elastic modulus, heat resistance, wear resistance, etc. are greatly improved, and can be used as engine parts
3. Foam aluminum alloy: Foamed aluminum alloy is a porous material with numerous air bubbles distributed in the metal matrix.
3. Difficult challenges for aluminum alloy applications
Expanding the application of aluminum alloys in automobiles will produce huge economic and social benefits, but there are still the following problems to be solved urgently:
(1) The performance of the aluminum alloy sheet needs to be improved
(2) Establish a database of aluminum alloys for automobiles
(3) Develop the design method, structural calculation method and forming process of aluminum alloy parts
(4) Improvement of aluminum alloy welding process
(5) Study the surface morphology of aluminum alloy materials, pre-treatment before painting, and anti-aging after painting.
(6), anti-corrosion effect and other issues, the accumulated data provides basic data for the formulation of the process of aluminum alloy application
(7) The maintenance market lacks experience and methods for the restoration, restoration principles and repair welding after the collision of aluminum alloy structural parts and covering parts after collision.