Aluminium Alloy Rolling with In-Line Solution Treatment and Quenching
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for manufacturing aluminium alloy rolled products, such as those of the 2XXX-, 6XXX-, and 7XXX-series, require expensive hardware and complex logistical systems due to multiple processing steps, including solution heat treatment, which can lead to variations in mechanical properties and increased costs.
Innovation Solution
A method involving semi-continuous casting of rolling ingots with preheating and homogenization to a peak metal temperature, followed by hot rolling with controlled temperatures to maintain soluble elements in solid solution, and quenching without subsequent solution heat treatment, simplifying the process and reducing costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If traditional multiple processing steps including solution heat treatment are used, then mechanical properties and quality are improved, but manufacturing cost and process complexity increase
Solution Approach 1:
The patent combines the hot rolling process with solution heat treatment into a single integrated process. The hot rolling is performed at temperatures that simultaneously achieve both deformation and solution treatment effects, eliminating the need for separate solution heat treatment step. This merging reduces process complexity while maintaining the mechanical properties that would otherwise require multiple distinct processing steps.
2Manufacturing precision
If multiple processing steps are used, then product quality is improved, but manufacturing cost increases
Solution Approach 1:
The patent merges hot rolling with solution heat treatment into one process step, reducing the total number of processing steps required. This integration maintains product quality by ensuring proper dissolution of alloying elements during the rolling process itself, while simultaneously reducing manufacturing costs by eliminating the need for separate heat treatment equipment, energy consumption, and handling operations.
Solution Approach 2:
The hot rolling process is designed to serve multiple functions simultaneously: it performs both the mechanical deformation needed to achieve the desired product shape and the thermal treatment needed to dissolve alloying elements and prepare the microstructure. This multi-functionality reduces the number of dedicated process steps and equipment needed, thereby lowering manufacturing costs while maintaining quality.
3Stability of the object's composition
If solution heat treatment is performed separately, then soluble elements are brought into solid solution, but handling and logistical complexity increase
Solution Approach 1:
The patent combines the solution heat treatment function with the hot rolling operation. The ingot is heated to solution treatment temperatures and then rolled without being removed from the heating zone or subjected to separate heat treatment. This integration eliminates the need for separate handling, loading, and unloading operations associated with dedicated solution heat treatment furnaces, thereby reducing logistical complexity while ensuring complete dissolution of soluble elements like zinc, magnesium, manganese, and copper into solid solution.
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 method produces aluminium alloy sheets or plates with desirable engineering properties similar to those from traditional methods but with significant cost benefits by eliminating the need for solution heat treatment and annealing, while maintaining high strength and damage tolerance.
Implementation Method 1
preheating and homogenizing of the rolling ingot at a peak metal temperature (PMT) and whereby afterwards said aluminium alloy after said preheating and homogenizing has a specific energy associated with a differential scanning calorimetry (DSC) signal less than 2 J/g in absolute value
Implementation Method 2
heating from ambient temperature to a target solution heat treatment temperature for solution heat treating (SHT) of the rolled product to bring as much as possible all or substantially all portions of the soluble elements like zinc, magnesium, manganese and copper into solid solution
Implementation Method 3
rapid cooling the SHT rolled product, preferably by one of spray quenching or immersion quenching in water or other suitable quenching media to a temperature of 175°C or lower, and preferably to ambient temperature, to prevent or minimise the uncontrolled precipitation of secondary phases in the aluminium alloy
Implementation Method 4
ageing, i.e. natural ageing or artificial ageing or a combination thereof, of the rolled product, for example to a T3, T4, T6, T7 or T8 condition depending on the heat-treatable aluminium alloy and condition desired
Data Source
Figure 1
Figure 2
AI summary
The invention relates to a method of manufacturing an aluminium alloy rolled product of a heat-treatable aluminium alloy having a thickness of at least 1 mm, comprising the steps of: semi-continuous casting a heat-treatable aluminium alloy into a rolling ingot having a thickness of at least 250 mm; homogenizing of the rolling ingot to a peak metal temperature (PMT) and whereby said aluminium alloy has a specific energy associated with a DSC signal less than 2 J/g in absolute value; hot rolling of the rolling ingot in multiple hot rolling steps into a hot rolled product having a final rolling gauge of at least 1 mm, whereby the hot rolled product during at least one of the last three rolling steps has a temperature less than 50°C below PMT; quenching of the hot rolled product at final rolling gauge from hot-mill exit temperature to below 175°C; optionally stress relieving of the quenched and hot rolled product at final rolling gauge; and ageing of the quenched and optionally stress relieved hot rolled product.