Magnesium Alloy Sheet Warm Rolling With Large Pass Reduction
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Solution Overview
Problem
The development of magnesium alloy sheets is hindered by their poor processing performance at room temperature, requiring high-temperature hot rolling with multiple passes, low single-pass reduction, and slow rolling speeds, leading to high production costs and inefficiencies, as well as inadequate mechanical properties such as strength and ductility.
Innovation Solution
A high-efficiency rolling process with controlled rolling speeds of 10-50 m/min and rolling reductions of 40-90% per pass, combined with preheating and precise temperature control between 250-450°C, to achieve a finer grain structure and improved mechanical properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If hot rolling with multiple passes and small reductions is used, then the magnesium alloy sheet can be processed, but the production efficiency is low and production costs are high
Solution Approach 1:
The patent changes the temperature parameter from conventional hot rolling (above recrystallization temperature) to warm rolling (250-450°C), and adjusts the strain rate parameter to optimize the balance between plasticity and production efficiency. This parameter change enables larger single-pass reductions while maintaining material quality.
Solution Approach 2:
The patent inverts the conventional approach by using warm rolling instead of hot rolling, and by applying large reductions per pass instead of small reductions. This inversion of conventional parameters resolves the contradiction between processability and production efficiency.
2Productivity
If rolling speed is increased, then production efficiency improves, but plasticity of magnesium alloy decreases
Solution Approach 1:
The patent changes the temperature parameter to warm rolling range (250-450°C) which maintains material plasticity while allowing higher rolling speeds. This temperature parameter change decouples the trade-off between speed and plasticity.
Solution Approach 2:
The patent applies dynamic control of rolling parameters including variable rolling speeds (10-50 m/min) and progressive reductions, adapting the process conditions to maintain plasticity while maximizing production efficiency throughout the rolling sequence.
3Productivity
If conventional hot rolling process is used, then magnesium alloy sheet can be produced, but the mechanical properties such as strength and ductility are insufficient
Solution Approach 1:
The patent changes the temperature parameter from hot rolling to warm rolling (250-450°C), which enables better control of microstructure and mechanical properties. The warmer (not hot) temperature maintains plasticity while the controlled cooling and deformation produce finer grain structures with superior strength and ductility.
Solution Approach 2:
The patent replaces the conventional hot rolling mechanical process with a warm rolling process that incorporates controlled deformation and microstructure evolution, substituting simple thermal-mechanical processing with a more sophisticated process that achieves superior mechanical properties.
4Ease of manufacture
If multiple passes with small reductions are applied, then the sheet can be rolled, but the number of passes increases to over ten
Solution Approach 1:
The patent changes the temperature and strain rate parameters to warm rolling conditions, which enable much larger single-pass reductions (total reduction ratio can reach 4:1 or more in just 3-5 passes). This parameter change directly reduces the number of passes required.
Solution Approach 2:
The patent inverts the conventional approach of many small reductions by applying few large reductions per pass through warm rolling, completely reversing the traditional multi-pass hot rolling methodology and achieving the same or better quality in significantly fewer passes.
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
This process enhances the strength and ductility of magnesium alloy sheets, reduces production time and costs, and simplifies the rolling process, making it suitable for large-scale industrial production.
Implementation Method 1
the plasticity of magnesium alloys decreases with the increase of strain rate... rolling speed commonly used in rolling magnesium alloys (the rolling speed is usually less than 5 m/min)... grain size of the magnesium alloy hot rolling sheet is controlled so as to enhance its comprehensive mechanical properties
Implementation Method 2
preheating the billets before rolling in each rolling pass and controlling both preheating temperature before rolling and rolling temperature in each rolling pass to be 250 ̃450° C.
Data Source
AI summary
The present disclosure provides a high-efficient rolling process for magnesium alloy sheet. Parameters of the rolling process are: the rolling speed of each rolling pass is 10-50 m/min, the rolling reduction of each rolling pass is controlled to be 40-90%, and both the preheating temperature before rolling and the rolling temperature of each rolling pass are 250-450° C. The present disclosure also provides a preparation method for magnesium alloy sheet, comprising: 1) preparing rolling billets; 2) high-efficient hot rolling; and 3) performing annealing. The rolling process can improve the mechanical performance especially, the strength and ductility of the sheet.