What is Heat Treatment

Jun 11, 2024 | Know-How

The Challenge

Kingston University design student Benny approached Maybrey Precision Castings with an innovative aluminium door handle concept that formed part of his final-year project. Having already produced a 3D printed prototype complete with the appropriate draft angles for sand casting, the initial objective was to manufacture a sample casting to validate the design.

Following the successful sample, Benny wanted to progress to a production-ready solution. As a student working within a limited budget, commissioning a professionally manufactured pattern was not financially viable, so he made the decision to manufacture the pattern himself at the Kingston University workshop.

To achieve a fully functional casting, the door handle required a hollow section at one end to accommodate the fixing mechanism. This introduced an additional level of complexity, requiring not only a pattern but also a correctly designed core box and core print arrangement to produce and accurately locate the sand core within the mould.

Our Solution

Working closely with Benny throughout the project, our technical team provided guidance at every stage of the tooling design process. Through a series of video calls, we discussed the complete pattern design, including impression layout, moulding box size, pattern orientation and the overall setup required for successful production.

Particular attention was given to the design of the core box and core prints. We explained how the positive core print on the pattern and the corresponding negative feature within the core box would accurately locate the sand core during mould assembly, ensuring the finished casting incorporated the required hollow section.

Using this guidance, Benny produced the complete pattern and core box design in CAD before submitting it to Maybrey Precision Castings for technical review and approval. Once approved, the tooling was manufactured at the Kingston University workshop.

Collaboration and Delivery

With the tooling complete, Benny visited our foundry in Aylesford, where he experienced the complete sand-casting process first-hand. Working alongside our experienced foundry team, he was shown each stage of production, from mould preparation and pattern setup through to core placement, aluminium melt preparation and the pouring of the moulds.

This collaborative approach enabled Benny to see how design decisions made during the development phase directly influenced the manufacturing process, providing valuable practical experience that cannot be gained in a classroom environment alone.

The Result

The finished aluminium castings met the design requirements and demonstrated a successful transition from concept, through tooling design, to completed cast components.

Benny was delighted with the finished door handles, which were exhibited at Kingston University's end-of-year showcase. The quality of his project led to his selection to exhibit at the prestigious New Designers Show in London, where emerging designers from across the UK present their work to industry professionals.

This project demonstrates Maybrey Precision Castings' commitment to supporting innovation and developing the next generation of engineers and product designers. By sharing our technical expertise and working collaboratively throughout the design and manufacturing process, we helped transform a student's concept into a professionally manufactured product ready for national exhibition.

Whether restoring history, supporting innovation or creating something entirely new, Maybrey Precision Castings combines traditional foundry craftsmanship with modern engineering expertise to turn ambitious ideas into exceptional castings.

Heat treatment is a controlled process of heating and cooling a casting to alter its microstructure and, with it, its mechanical properties. It is carried out after the casting has cooled and been removed from the mould, and before it moves to final inspection and despatch.

Not every casting requires heat treatment. But for applications where specific mechanical properties, stress relief, or dimensional stability are required, it is an essential part of the production process. At Maybrey, we carry out heat treatment in-house as part of our post-process capability.

The Main Types of Heat Treatment

Stress Relief and Annealing

Casting involves rapid solidification from high temperatures, which can leave residual stresses in the material. These stresses can cause distortion, cracking, or dimensional instability during subsequent machining or in service. Stress relief annealing heats the casting to a moderate temperature, holds it there long enough for the stresses to dissipate, and then cools it slowly. The result is a more stable, dimensionally consistent casting.

Full annealing takes the casting to a higher temperature and cools it more slowly still, producing maximum softness. This is used where the casting needs to be worked further, or where machinability is the priority.

Solution Treatment and Ageing

For aluminium alloys, heat treatment is frequently used to develop the material's full mechanical potential. Solution treatment heats the casting to a temperature at which the alloying elements dissolve into the aluminium matrix, then quenches it rapidly to retain them in solution. This alone produces a supersaturated and relatively soft condition.

Ageing, either at room temperature (natural ageing) or at elevated temperature (artificial ageing), causes the dissolved elements to precipitate out as fine particles within the matrix. This precipitation hardening is what gives aerospace aluminium alloys their characteristic combination of low weight and high strength. The T6 condition, solution treated and artificially aged, is the most widely used specification for aerospace aluminium castings.

Heat Treatment at Maybrey

We carry out stress relief, annealing, solution treatment, and ageing in-house for both ferrous and non-ferrous castings. Our heat treatment operations are covered by our ISO 9001:2015 and AS9100 Rev D quality management systems. For aerospace castings, heat treatment procedures are specified at the contract review stage and form part of the full traceability record that accompanies each batch.

Explore our full Post-Process capability

 

Maybrey Achieves Future Net Zero Platinum Award

Maybrey Precision Castings, as part of the Caro Group, has been awarded the Future Net Zero Platinum Award: the highest level of the FNZ programme and the most rigorous independent certification available for carbon reduction in UK manufacturing. The Platinum award...

read more...

We can take your casting through to finished component: machined, coated, tested, and ready to fit.