Performance comparison of aluminum magnesium alloy powder metallurgy components (such as suspension arms and steering knuckles) in automotive lightweighting

Suspension arm: innovation from steel stamping parts to aluminum magnesium alloy powder metallurgy

Steel suspension arm: with a density of 7.8 g/cm ³, it relies on complex stamping welding processes to form, with a mass of about 3-5 kg (for medium-sized vehicles). Although it has high strength (yield strength of 250-350 MPa), the large mass under the spring leads to delayed handling response and is prone to corrosion (requiring multi-layer coating protection).

Aluminum magnesium alloy powder metallurgy suspension arm: Using powder metallurgy hot pressing aging strengthening process, aluminum magnesium alloy powder (such as AZ31 component) is mixed with a small amount of Si and Cu elements and densified at 450 ℃ and 100 MPa. Performance advantages include:

Lightweight: The weight is reduced to 1.5-2.5 kg, with a weight reduction of 40% -60%. The decrease in unsprung weight directly improves the tire grounding efficiency (which can reduce the amplitude of bumps by 10% -15%).

Mechanical properties: The tensile strength reaches 280-320 MPa (surpassing low carbon steel), and the fatigue life exceeds 500000 times (about 300000 times for steel parts), meeting the alternating load requirements under complex road conditions (such as bending stress when passing over bumpy roads).

Integrated design: Powder metallurgy can form hollow cavities and complex rib structures, reducing assembly processes (such as eliminating liner welding steps), while improving corrosion resistance through surface micro arc oxidation (salt spray life increased from 500 hours to 1200 hours).

Steering joint: aluminum magnesium alloy powder metallurgy vs. aluminum alloy casting

Aluminum alloy cast steering knuckle: using low-pressure casting technology, with a density of 2.7 g/cm ³, a mass of about 2-3 kg, and a tensile strength of 220-260 MPa. However, the casting is prone to shrinkage defects and is prone to fracture under steering impact loads (such as emergency lane changes).

Aluminum magnesium alloy powder metallurgy steering joint: A complex internal cavity structure is prepared by powder injection molding (MIM), with a density of 1.8-2.0 g/cm ³ and a mass of only 1.2-1.8 kg, which is 30% -40% lighter than aluminum alloy casting. Key performance improvement:

Impact toughness: The impact absorption energy has been increased from 25 J to over 40 J, and it can withstand instantaneous loads during sudden turns (such as 50 km/h lateral impact).

Dimensional accuracy: The powder metallurgy tolerance is controlled within ± 0.05 mm, reducing the machining amount (cutting allowance from 3 mm to 0.5 mm), while avoiding assembly stress caused by common dimensional deviations in castings.