Method of manufacturing a 7xxx-series aluminium alloy plate product having improved fatigue failure resistance

Pending Publication Date: 2021-08-12
NOVELIS KOBLENZ GMBH
View PDF0 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Benefits of technology

[0073]Accordingly, the plate product manufactured according to the invention provides improved properties compared to a plate product manufactured

Problems solved by technology

However, this US patent does not deal with the property of fatigue failure resistance of the AA7055 alloys.
Each type of inspection is very costly, because the aircraft must be taken out of service for the inspect

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Method of manufacturing a 7xxx-series aluminium alloy plate product having improved fatigue failure resistance
  • Method of manufacturing a 7xxx-series aluminium alloy plate product having improved fatigue failure resistance

Examples

Experimental program
Comparison scheme
Effect test

example

[0077]Rolling ingots have been DC-cast of the aluminum alloy AA7055, with a composition as given in Table 1

TABLE 1LotSiFeCuMgZnZrA, B, C, D, E0.070.072.351.948.050.12

[0078]The rolling ingots had a thickness of about 400 mm. Homogenization of the ingots was carried out in a two-step homogenization procedure at 465° C. (first step) and 475° C. (second step) followed by cooling to ambient temperature. After scalping, the ingots were pre-heated to 410° C. for hot rolling. Hot rolling was carried out on a hot rolling mill having a work roll radius of about 575 mm. Lots A and B were processed in accordance with the invention, i.e. both lots receive a high reduction pass during the hot rolling process. During the high reduction rolling pass, lot A received a thickness reduction of about 30% (167 mm to 117 mm) and lot B received a thickness reduction of about 28% (165 mm to 118 mm). The rolling speed during this high reduction pass was about 25 m / min giving a deformation rate of about 0.53 ...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

PropertyMeasurementUnit
Temperatureaaaaaaaaaa
Lengthaaaaaaaaaa
Lengthaaaaaaaaaa
Login to view more

Abstract

The invention relates to a method of manufacturing an 7xxx-series aluminium alloy plate product having improved fatigue failure resistance, the method comprising the steps of (a) casting an ingot made of an aluminium alloy of the 7xxx-series comprising (in wt. %): Zn 5 to 9, Mg 1 to 3, Cu 0 to 3, balance aluminium and incidental elements and impurities; (b) homogenizing and/or preheating the cast ingot; (c) hot rolling the ingot into a plate product by rolling the ingot with multiple rolling passes, characterized in that when the intermediate thickness of the plate is between 80 and 220 mm, at least a high reduction hot rolling pass is carried out with a thickness reduction of at least 25%, wherein the plate product has a final thickness of less than 75 mm. The invention is also related to an aluminium alloy plate product and an aerospace structural member produced by this method.

Description

FIELD OF THE INVENTION[0001]The invention relates to a method of manufacturing a 7xxx-series aluminium alloy plate product having improved fatigue failure resistance. The plate product can be ideally applied in aerospace structural applications, such as wing skin panels and members, and other high strength end users.BACKGROUND OF THE INVENTION[0002]Al—Zn—Mg—(Cu) type alloys or AA7xxx-series alloys have been used for aircraft constructions for more than 50 years, and particularly for wing members, for example, inter alia, AA7055-series alloys have been used. These aluminium alloys possess a required balance of strength, fracture toughness and corrosion resistance, and are especially well suited for structural aerospace applications such as wing upper skin panels. This is disclosed for example in U.S. Pat. No. 5,221,377. This US patent discloses that in order to obtain these high mechanical characteristics, it is necessary to subject the alloys to a three-stage artificial ageing proce...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
IPC IPC(8): C21D8/02C21D9/46B22D7/00C22C21/10
CPCC21D8/0226C22C21/10B22D7/005C21D9/46C22F1/053
Inventor SPANGEL, SABINE MARIAMEYER, PHILIPPEBÜRGER, ACHIMRÜBNER, MATTHIASLACHNITT, SIMON
Owner NOVELIS KOBLENZ GMBH
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap