US 12,291,768 B2
Fast ageing method for stamped heat-treatable alloys
Nan Li, London Greater London (GB); Jinghua Zheng, London Greater London (GB); Kailun Zheng, London Greater London (GB); Jianguo Lin, London Greater London (GB); and Catrin Davies, London Greater London (GB)
Assigned to IMPERIAL INNOVATIONS LIMITED, London (GB)
Appl. No. 15/749,680
Filed by IMPERIAL INNOVATIONS LIMITED, London (GB)
PCT Filed Aug. 5, 2016, PCT No. PCT/GB2016/052451
§ 371(c)(1), (2) Date Feb. 1, 2018,
PCT Pub. No. WO2017/021742, PCT Pub. Date Feb. 9, 2017.
Claims priority of application No. 1513832 (GB), filed on Aug. 5, 2015.
Prior Publication US 2018/0223405 A1, Aug. 9, 2018
Int. Cl. C22F 1/05 (2006.01); C22C 21/02 (2006.01); C22C 21/06 (2006.01)
CPC C22F 1/05 (2013.01) [C22C 21/02 (2013.01); C22C 21/06 (2013.01)] 5 Claims
OG exemplary drawing
 
1. A method of pressing a formed component from a sheet material, comprising forming a material into a desired geometry, the method including artificially ageing the formed component, wherein the material is a heat treatable aluminium alloy, wherein the formed component is formed using the method by sequential steps of being heated to its solution heat treatment temperature, then being formed into the desired geometry by being hot stamped once, and subsequently being quenched in cold dies, wherein, after forming of the formed component, the formed component is artificially aged using an ageing method which comprises the steps of:
(a) applying a pre-ageing heat treatment by heating the formed component according to a predefined temperature profile, wherein the temperature profile comprises a varying target temperature; and, subsequently, (b) applying a paint bake cycle to the formed component, and
wherein the predefined temperature profile of step (a) comprises a first period and a second period, wherein the target temperature during the first period is a constant target temperature in the range 50° C. and 130° C., or wherein the target temperature during the first period is a variable target temperature which is less than the Guinier-Preston solvus temperature, wherein the target temperature during the second period is between 180° C. and 270° C., the target temperature during the second period is constant and the target temperature during the second period exceeds the Guinier-Preston solvus temperature, wherein the first period has a duration of less than 60 minutes, wherein the ageing method increases a post-form strength of the formed component; and
wherein the ageing method results in a post-form yield strength of the formed component of greater than 240 MPa.