Aluminum Alloy Fin Material Springback Control
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Solution Overview
Problem
Existing aluminum alloy fin materials for heat exchangers face challenges in achieving a balance between thinness, high strength after brazing, and minimal springback during corrugation, while maintaining erosion resistance and sacrificial anodic effects.
Innovation Solution
A specific composition of aluminum alloy with Si: 0.9 to 1.2%, Fe: 0.8 to 1.1%, Mn: 1.1 to 1.4%, and Zn: 0.9 to 1.1%, combined with a production method involving continuous thin slab casting, hot rolling, and controlled annealing, to achieve a final sheet thickness of 35 to 50 μm, suppressing springback and enhancing formability and strength.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the fin material is reduced in thickness to achieve thinner fins, then the heat exchanger performance is improved, but the springback increases making corrugation difficult
Solution Approach 1:
The patent changes the chemical composition parameters of the aluminum alloy by precisely controlling the content ranges of Si (0.7-1.3 wt%), Fe (2.0-2.8 wt%), Mn (0.6-1.2 wt%), and Zn (0.02-1.5 wt%). This composition optimization modifies the material's mechanical properties to reduce springback while maintaining thin gauge capability, allowing fins to be made thinner without compromising formability during corrugation
2Strength
If Fe content is increased to over 2.0 wt% to improve strength, then the tensile strength increases, but coarse Al-(Fe.Mn)-Si-based precipitates are formed making sheet production difficult
Solution Approach 1:
The patent optimizes the composition parameters by setting Fe content to 2.0-2.8 wt% in combination with specific ranges of Si (0.7-1.3 wt%), Mn (0.6-1.2 wt%), and Zn (0.02-1.5 wt%). This balanced composition control prevents excessive coarse precipitate formation while achieving the required tensile strength, enabling successful sheet production through controlled solidification and rolling processes
Solution Approach 2:
The patent creates a multi-element aluminum alloy composite system containing Al, Si, Fe, Mn, and Zn in specific proportions. This composite composition synergistically controls precipitate formation and distribution, allowing high strength to be achieved without the formation of excessive coarse Al-(Fe.Mn)-Si-based precipitates that would complicate sheet production
3Weight of moving object
If the fin material is made thinner, then the heat exchanger weight is reduced, but the formability during corrugation deteriorates
Solution Approach 1:
The patent modifies the material composition parameters to optimize the balance between thickness reduction and formability. By controlling Si (0.7-1.3 wt%), Fe (2.0-2.8 wt%), Mn (0.6-1.2 wt%), and Zn (0.02-1.5 wt%), the alloy achieves improved ductility and reduced springback characteristics, enabling thin fins to be successfully corrugated without compromising formability
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution results in an aluminum alloy fin material with reduced springback, suitable strength before brazing, high strength after brazing, and improved erosion and corrosion resistance, effectively addressing the limitations of previous materials.
Implementation Method 1
annealing it two times or more by intermediate annealing
Data Source
AI summary
An aluminum alloy fin material for heat exchanger use having a 35 to 50 μm thickness, a small springback at the time of corrugation, a suitable strength before brazing enabling easy fin formation, a high strength after brazing, and excellent erosion resistance, self corrosion resistance, and sacrificial anodic effect and a method of production of the same are provided. A fin material containing, by mass %, Si: 0.9 to 1.2%, Fe: 0.8 to 1.1%, Mn: 1.1 to 1.4%, and Zn: 0.9 to 1.1%, further limiting the impurity Mg to 0.05% or less, Cu to 0.03% or less, and ([Si]+[Fe]+2[Mn])/3 to 1.4% to 1.6%, and having a balance of unavoidable impurities and Al. A method of production prescribing hot rolling, cold rolling, intermediate annealing, and final cold rolling.