Multi Axial Creep Fatigue Damage Accumulation in Vacuum Brazed Battery Pack Cooling Structures
Vacuum brazed aluminum cooling plates fail under coupled multi-axial creep-fatigue when pressure pulses interact with static cell swelling constraints.
Al 3003 Core
Meaning
Manganese-bearing aluminum alloys provide structural strength and fluid isolation within brazed thermal management assemblies. The material specified as Al 3003 core forms the central structural sheet in roll-bonded brazing sheet composites used in battery cooling plates. This layer provides mechanical rigidity and containment, while lower-melting outer layers melt during processing to form sealed fluid channels.
The material specification defines iron, silicon, and manganese limits to ensure high solidus temperatures during thermal joining.
Mechanical Function
High manganese content provides moderate yield strength and high formability during cold stamping operations. Roll bonding integrates the Al 3003 core between sacrificial cladding layers prior to stamping into heat exchanger channels. Processing at elevated temperature forms a dense band of iron-manganese precipitates at the interface that limits silicon diffusion into the central matrix.
Corrosion Resistance
Electrochemical potential differences between internal layers and outer surface cladding direct galvanic attack horizontally across the exterior surface. When exposed to glycol coolants, Al 3003 core acts as a noble barrier relative to sacrificial zinc-bearing clad alloys.
Thermal Threshold
Solidus temperatures above six hundred degrees Celsius prevent core melting during controlled atmosphere brazing. High temperature exposure recrystallizes the grain structure, lowering yield strength to soft temper levels.