7xxx Aluminum Alloy T4 Temper Stabilization for Long-Term Formability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
7xxx series aluminum alloy products in T4 temper are unstable and lose formability quickly, making them unsuitable for long-term use in manufacturing due to rapid hardening, which limits their application in industries requiring high strength and light weight.
Innovation Solution
A method involving casting, homogenization, rolling, solutionizing, and pre-aging at temperatures ranging from 60 °C to 130 °C for up to 24 hours, followed by slow cooling, to produce 7xxx series aluminum alloy products that maintain stability and formability for up to six months.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If 7xxx series aluminum alloy products are supplied in T4 temper with solutionizing and natural aging, then formability at room temperature is improved, but the product hardens quickly within a few days and loses formability
Solution Approach 1:
The patent applies preliminary action by introducing a pre-aging step before coiling. The alloy is heated to 60-130°C for up to 24 hours to precipitate Guinier-Preston zones in advance, which stabilizes the T4 temper and prevents rapid hardening that would otherwise occur within a few days of production.
Solution Approach 2:
The patent changes the temperature parameter by introducing controlled heating to 60-130°C during pre-aging. This temperature range is specifically selected to promote GP zone formation without causing excessive hardening, thereby extending the stable formability period from days to months.
2Ease of manufacture
If 7xxx series aluminum alloy products are supplied in F temper (as-fabricated), then no solutionizing is needed, but users must solutionize and hot form the product themselves
Solution Approach 1:
The patent performs solutionizing and pre-aging at the manufacturing stage before delivery to users. This preliminary action provides ready-to-form material with stable T4 temper, eliminating the need for users to perform solutionizing and hot forming operations.
3Strength
If 7xxx series aluminum alloy products are supplied in T6 temper with solutionizing and artificial aging, then strength is improved, but formability at room temperature becomes quite low
Solution Approach 1:
The patent changes the aging parameter by using natural aging at ambient temperature instead of artificial aging at elevated temperatures. This parameter change produces T4 temper with adequate strength and superior formability compared to T6 temper.
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 method results in 7xxx series aluminum alloy products that retain desirable formability and strength for an extended period, allowing for easier integration into manufacturing cycles and reducing production costs by avoiding the need for immediate processing after production.
Implementation Method 1
solutionizing and, then, pre-aging, the rolled aluminum alloy product, wherein the pre-aging comprises heating the rolled aluminum alloy product to a pre-aging temperature ranging from 60 °C to 130 °C
Implementation Method 2
solutionizing and, then, pre-aging, the rolled aluminum alloy product
Data Source
Figure 1
Figure 2
Figure 3A
AI summary
The present disclosure generally provides 7xxx series aluminum alloy products in a stable T4 temper. The disclosure also provides methods of making such products, for example, using processes that include a combination of casting, rolling, solutionizing, quenching, reheating, and slow cooling. The disclosure also provides various end uses of such products, such as in automotive, transportation, electronics, and industrial applications.