The HFQ Process
The HFQ® Process
Weight reduction has always been a goal of efficient structure design for vehicles and portable devices. In recent years the need to reduce weight has become more urgent because of the electrification of transport, sustainability and the drive for energy efficiency.
Aluminium, particularly in ultra-high strength grades (with yield strengths between 300-500 MPa), offers a means of achieving necessary light-weighting, provided that parts can be formed rapidly into complex geometries with high process capability.
Until the HFQ® process was developed, cold forming of aluminium in the sheet form was the main option available for mass production. Unfortunately, the high strength grades of aluminium have limited formability in the cold state and also suffer from spring-back. Accordingly cold-formed aluminium parts had to be designed in multiple pieces, or with limited geometry complexity; whilst also needing complicated and unreliable spring-back compensation in the tool or additional restrike operations. The HFQ® process was developed to overcome the formability limitation of high strength aluminium alloys. By forming the alloy in a very soft viscoplastic state (at 400-550 °C) whilst simultaneously quenching to room temperature, extremely challenging geometries with high depth of draw and tight radii are possible without any appreciated spring-back. Greater depth and sharper radii lead to improved vehicle structural stiffness and potentially packaging efficiency.
Step-by-step HFQ® process
The hot forming process of aluminium alloys comprises four primary steps, executed on a bespoke sheet blank: solutionising, blank transfer, forming and quenching, and finally artificial aging.
Step 1:
Solutionising
Step 2:
Blank transfer
Step 3:
Forming and quenching
Step 4:
Artificial aging
Initially, the developed blank is heated in a furnace to a temperature conducive to dissolving the precipitates within the material. Notably, solutionising ovens are most efficient when employing forced convection, a difference from those utilised in press-hardened steel lines.
The pressing operation is conducted using a high-speed hydraulic, servo-hydraulic, or servo press, wherein the forming tool is cooled to facilitate the requisite quenching for maintaining alloying elements in solid solution. Subsequently, the aging process fosters precipitation, enhancing the strength of components to meet the specified criteria, typically ranging from 300 to 500 MPa yield, contingent upon the aluminium alloy employed. Tailored proprietary aging processes have been developed to optimise corrosion resistance and/or downstream joining properties.
Post HFQ® processing, parts may undergo in-die trimming or laser trimming, akin to procedures typical for press-hardened steel parts, with the choice often dependent on production volume. Laser trimming is commonly preferred for volumes below 10,000 parts per annum due to the substantial cost of trim tooling, or for higher volumes when flexibility is desired for future design modifications, such as hole positioning.
While the primary benefit of the HFQ® process lies in facilitating the production of complex, deep-drawn pressings in a single forming operation, it remains feasible to conduct secondary cold pressing operations after the HFQ® stage, should the need arise.
Finding a manufacturing partner
HFQ Technology Associates can provide OEMs with a range of options for HFQ® components supply. For high volume applications our HFQ® tier partners including fischer group in Germany and Jet Wagon in China have accredited HFQ® lines that can provide capacity exceeding 250,000 units per annum; and HFQ-TA are working with other tiers to develop a global network of accredited HFQ® plants. OEMs do have the option to install their own HFQ® lines or have a preferred tier adopt the technology with support from HFQ-TA.
Through the HFQ® Partner Network, you can browse partners equipped to deliver HFQ® parts or associated services for automotive, aerospace, consumer goods, and more. Discuss your custom requirements to determine the optimal HFQ® partner for prototyping or volume production.
Our manufacturing capability
HFQ-TA has created a Global Technology Centre in Coventry with the world’s first HFQ® line, configured for flexibility, that can provide prototypes and volumes up to 50,000 units per annum. This full-scale line has been making series production parts for automotive OEMs since 2016. The press line also serves as a training and demonstration facility for our global tiers and OEM clients.
Our Coventry line, supported by a team of technical experts can host HFQ® part manufacture whilst tiers or OEMs install their own accredited HFQ® lines.
Designing with HFQ® in mind
To achieve lowest cost and design efficiency, early consultation on a component design is strongly recommended. Our experienced applications engineers and technical specialists can provide feasibility guidance based on early CAD models; our team will then provide feedback design optimisation for HFQ, including geometrical changes, alloy suggestions and options for part integration.
Ask us about sustainable lightweighting
We welcome enquiries from OEMs, tiers, design consultancies and alloy producers looking for a new approach to reduce cost, complexity and carbon footprint. Our technical experts will be pleased to arrange a consultation and provide initial guidance.