Hot form quench

Hot Form Quench (HFQ®) - an aluminium hot forming lightweighting technology - is an industrial stamping process for the production of deep drawn, precise and complex geometry ultra-high strength aluminium sheet components. It is the aluminium hot stamping (sometimes also called 'aluminium hot forming') process for age-hardening grades of sheet and has similarities to the press hardening of ultra-high strength steels. HFQ, the original aluminium hot stamping process, exploits viscoplasticity of aluminium at high temperatures to facilitate the production of lightweight structures, often replacing steel, composites, castings, extrusions or multiple cold formed pressings.

Hot Form Quench (HFQ) is an aluminum hot stamping process for high strength sheet (typically) 2xxx, 6xxx and 7xxx series alloys, that was initially developed in the early 2000s by Professors Jianguo Lin and Trevor Dean at the University of Birmingham and then at Imperial College London, both in the UK.

HFQ Technology Associates (the trading name of Diteven Limited), a materials technology company based in the UK, has exclusive commercialisation rights for HFQ aluminium hot forming, having acquired in 2024 the assets and know-how from Impression Technologies Limited (ITL) and Imperial College. Shortly after the first HFQ applications were adopted in automotive applications (the Aston Martin DB11) in 2016, other organisations in the lightweighting ecosystem joined Impression Technologies on a Horizon 2020 programme called LoCoMaTech with an aim to take the HFQ Technology towards mass volume applications. ITL, having installed the world's first HFQ line at the old Jaguar site at Lyons Park Coventry, licensed the HFQ Technology around the world to manufacturers, such as fischer group in Germany, EMI Aerospace in US, and Jet Wagon in China, supplying the automotive and aerospace sectors.

Hot forming of aluminium alloys consists of four main steps performed on a custom-shaped sheet blank: heating and solutionising (above 450°C), blank transfer, quenching (to near ambient temperature in a cool die) and forming, and artificial aging. In the solutionising step, the blank is heated in a furnace to a temperature where the precipitates in the material dissolve. The solutionising ovens are most effective when designed with forced convection, which is a difference to those used for press hardened steel lines. It is important to note that this hot forming process is different to what is termed Warm Forming, which is performed at under 300 °C and results in less formability and finished part strength.

The pressing operation is carried out in a high speed hydraulic, servo-hydraulic or servo press in which the forming tool is cooled to create the necessary quenching to maintain the alloying elements in solid solution. The subsequent ageing process enables precipitation and increases the strength of the components to the required level, typically 300 to 500MPa yield, depending on the aluminium alloy used. Customised proprietary ageing processes have been developed to optimise corrosion performance and/or downstream joining properties

Following the HFQ process, parts can be in-die trimmed or laser trimmed as is typical for press hardened steel parts, dependant on production volume. It is usual for volumes below 10,000 parts per annum to be laser trimmed because of the high cost of the trim tooling; or for higher volumes if flexibility is required for future design changes, such as hole positioning.

Although a key benefit of the HFQ process is to enable the production of complex, deep drawn pressings in a single forming operation, it is possible to perform secondary cold pressing operations after the HFQ stage if required.

HFQ is used where light-weighting and high levels of part integration are required where aluminium sheet is considered a suitable technical and economic proposition. HFQ can be a solution for applications ranging from several hundred to millions of parts per annum. Aluminium sheet thickness ideal for HFQ range from 0.8mm to 5.0mm.