Also this year, the Association of Italian Metalworkers (Associazione Italiana di Metallurgia – AIM) launched its 2020 Aldo Daccò Prize. The award was first established in 1975 to stimulate the sector’s technicians to contribute to the progress of foundry and solidification techniques through essays and original studies. Due to the restrictions in force, the award ceremony was held online on January 18^th, 2020 on the occasion of the opening ceremony of the 38^th AIM national congress.

In the 2020 edition of the Aldo Daccò Prize, Marco was awarded ex-aequo with Engr. Lavinia Tonelli and presented the scientific paper Compensation of Shrinkage Deformation in Zinc Alloy Die-Cast Components.

We interviewed him to learn more about his paper and compliment him on the great result obtained.

Tell us something about the contest you participated in – what is it and why did you decide to compete?

AIM is a non-profit cultural body and was founded in January 1946 with the aim of spreading the science and technology of metallic and other engineering materials. In the wake of its mission, AIM has been organizing this competition for 45 years. I have always followed it for personal interest and I have been looking forward to participating in it for a long time. Having worked at Bruschi Spa for the last few years, I decided to combine my technical knowledge and the experience developed in the field to contribute to the development of the knowledge of foundry and solidification techniques.

What does your paper deal with?

The paper presented is entitled: Compensation of Shrinkage Deformations in Zinc Alloy Die-Cast Components. In particular, it focuses on a specific criticality of zinc alloy die casts, i.e. the occurrence of product deformations caused by the shrinkage of material in the post-molding phase. In the paper I highlighted the difficulties encountered and the possible methods of solving this problem.

Why did you decide to develop precisely this topic?

The problems dealt with in my paper emerged during the inspection of particular products at Bruschi Spa. These problems were first discovered by our Quality Engineer Andrea Salmistraro. During the component analysis phase (performed with a 3D scanner), he noticed that some important dimensions were altered by a defect due to alloy deformation. Thanks to the involvement and contribution of our Strategic Technology Manager Ermo Fusè we hypothesized and subsequently demonstrated that this defect was related to shrinkage caused by Zamak solidification, which varies depending on mass distribution in the component. With my paper I intended to demonstrate that our solution makes it possible to counteract shrinkage deformations of material.

How did you get to the solution?

The first step was to verify that the mold did not have any alterations that could lead to this problem. Once the suitability of molds and sliders was ascertained, we analyzed two practical cases in which the components presented the same problem – despite their clearly different geometric characteristics:

• Flat surface deformation: in this case we started by scanning the deformed piece. Thanks to a CAD software, we extrapolated a lattice and used it to digitally reconstruct the deformed surface and then symmetrize it to obtain a counter-deformed surface. Finally, we applied this surface to the corresponding molding insert surface in order to obtain a piece deformed in the opposite direction and – once cooled – a compliant die cast.
• Cylindrical surface deformation: we followed a procedure similar to the previous one, even if it was not possible to replicate and symmetrize the deformed surface due to geometry complexity. We then scanned the pieces to identify the deformed areas and – after delimiting them with our CAD software – we projected them directly onto the molding insert surface and lastly we counter-deformed them.

Your paper suggests that the deformations addressed are in the order of tenths or even hundreds of a millimeter – how did you guarantee the finish’s precision?

Thanks to his many years of experience and in-depth knowledge of the equipment, our CAM toolmaker and programmer Matteo Annovazzi was able to faithfully replicate the design. He created an accurate CAM program for the milling machine and he then used it to work the molds.

What do you think of this experience and of your victory?

I am very satisfied with the result. I am proud of the existence of entities committed to promoting progress, the exchange of ideas and the sharing of knowledge in this sector. I would also like to thank Bruschi Spa for allowing me to carry out the studies shown in this paper and the support received from the entire team. It is thanks to the collaboration of the various engineers and technicians of the Bruschi team that I was able to demonstrate that it is possible to counteract the deformations caused by material shrinkage by means of a voluntary and targeted counter-deformation of the molding insert surface that generate the surfaces affected by this problem. It is not my victory – it is a team victory.

The post Marco Galbiati awarded with the 2020 Aldo Daccò Prize appeared first on Bruschi.

EUROGUSS is the biggest European trade fair with focus on die casting and it draws visitors and exhibitors from all over the world, coming from a wide range of industries such as automotive, electronics and energy production.

Since its first edition in 1996, EUROGUSS has been steadily growing and expanded to the point of becoming the biggest European die casting trade fair in 2016, thanks to over 578 exhibitors and 12032 visitors attending.

The exhibit takes place every 2 years and it deals with innovative solutions for zinc die casting, magnesium die casting and aluminum die casting. New industrial techniques will also be displayed: quick prototyping, CNC machines, metal alloys, molds, peripheral equipment, process optimization, energy efficiency, material testing, die casting machines and 3D printers.

Moreover, the International Die Casting Congress will be held during the trade fair: a 3-day-long cycle of conferences, dealing with the most discussed themes of die casting industry.

Considering the size of the event, this participation is a great chance for Bruschi to create a new contact network and to keep up-to-date with new techniques and the most advanced production machines.

Regarding Bruschi participation, CEO Paolo Rastelli declares: “It is a great pleasure for me to lead Bruschi in the attendance of such an important convention. I believe it is a tangible sign of our company’s growth and I trust it will open new paths and business opportunities.”

At Bruschi’s stand visitors can take a look at some selected products, learn more about the company, leave their contact information and even schedule meetings with our representatives.

Bruschi’s stand will be placed in hall 6, block 320.

To reach the exhibit location is possible to travel by car, taxi or public transport. For further information on how to access the fair, you can check the designated page on EUROGUSS official website.

{{cta(‘90548e70-5fbe-47d0-802c-a042cefc67b6’)}}

The post Bruschi attending EUROGUSS 2018 appeared first on Bruschi.

To optimize the process and to successfully avoid the critical points in pressure die casting components, it is important to know the material reactions in every phase.

Parting line geometry

When arranging the parting line, that is given by the design of the component, the designer should consider the available position and length for the liquid metal to flow into the cavity. It is also important to remember that adequate gate area will be needed and if the gate length is restricted it will need to be thick with possible consequence of trimming problems. To overcome those problems, the solution could be changing the geometry of the component.

Section thickness
When designing a component, it is crucual to remember that thin walls could be proportionally stronger than thicker ones. That feature allows to use less material and can be produced more quickly in a cost saving way.

Section ratios
It is better to develop components with a fairly constant section thickness. Anyway, in real production, it is possible to make exceptions of this rule if the zinc die caster supplier has expertise and know how to do that.

Checking thickness ratios using the inscribed sphere technique
To avoid porosity the designer could reduce the ratio of inscribed sphere diameters.

Draft angles
Draft angles could be useful to prevent the casting sticking on the moving die. This precaution increases costs, but it is necessary to avoid secondary machining operations.

Design to assist die filling

During the consideration of the parting line of the component it is important to focus on the position and length available for the ingate. In fact good surface finishes and low porosity could be difficult to reach if the available position doesn’t give the chance for the metal to flow into every part of the casting.

Ribs
Strengthening a casting without thickening is possible with ribs, that should be rounded and blended and arranged to join adjacent sections.

Flat surfaces
Flat smooth surfaces are the most expansive design feature of zinc die casting production. There are many ways to manufacture a more attractive product, and at the same time to reduce the cost of production. Improving the collaboration between your designers and the right zinc die casting supplier, in a co-design activity, could help to reach goals without waste resources.

Crowning 

Slight crowning and rounding of the corners will reduce distortion in case of plain flat highly finished surface.

Textured Surfaces
To increase the surface quality is possible to choose surface effects.

Fillets and Blends
Sharp corners can be avoided using fillets to have a strengthening effect. It’s a common die casting practice to use a fillet with a minimum radius of 1.6 mm on inside edges. A slight radius on outside corners is an effective cost-saving measure.

Lettering
If lettering is required, it is better for designers to use raised lettering, instead of depressed lettering. Raised lettering allows to limit costs and minimize risks in terms of mold erosion.

Inserts
Placing cast in the die inserts slows down the process and increases costs, for this reason nowadays inserts are less used than in the past.

Dimensional Tolerances
One of the main advantages of the zinc die casting process is the ability to produce complex components with excellent precision in terms of smaller tolerances.

Best achievable linear tolerances
It’s really important to work closely with the die caster, in ongoing co-design activity, because during die casting process linear tolerance band within 0.1% of dimension are allowed at the 8 standard deviations confidence level. This dimension can be reached only when the geometry of the component is favorable to consistent shrinkage without distortion following the ejection from the die.

Design to avoid local die overheating
Designers should develop products or components paying attention to issues caused by die overheating, that can give surface porosity, drag marks and cracks.

How to avoid hot spots by good component design
Preventing heat developed in vulnerable areas is necessary a good design. The right zinc die casting supplier could help to reach goals with its technology and expertise.

Designing to avoid moving cores
Complex three-dimensional shapes are achieved by using moving cores, which slide in the die. If designers can achieve a sufficient effect without moving those cores, this will be a cost saving action.

Avoiding weak die features
It is not suggested to develop product or component using mold with weak features. It could be expensive in economic and time terms.

Cast screw threads
Secondary operations for threads are necessary in case of requirement an unscrewing core. In other cases the designer could choose if it is better to use casting or secondary machining.

Design for reliable die ejection
An ejector pin need to be put near where the casting will tend to grip the tool. It must ensure that the casting and the runner are moved squarely without distorting the component.

Bosses
Bosses heavier than thin walls give unequal shrinkage, creating “shrink marks” that are shallow depression on the face of the casting opposite to the thickened section.

Cored holes
Cored holes can eliminate drilling and machining during the casting.

Machining allowance
If the machining is unavoidable, it is recommendable an allowance of 0.25 mm.

To be updated on trends and innovations in the Zinc Die Casting industry, you are welcome to subscribe to our blog.

{{cta(‘90548e70-5fbe-47d0-802c-a042cefc67b6’)}}

Freely adapted from IZA

The post The critical points in pressure die casting components appeared first on Bruschi.

Bruschi mentioned on Italian newspapers

The awards won are the Nadca award for Excellence in Zinc Die Casting Over 6 oz at the International Die Casting Competition from the North American Die Casting Association and the European Zinc Die Casting Competition 2016 for Nespresso KitchenAid Artisan 5KES0503.

The outstanding Italian company Bruschi has distinguished itself for efficiency, accuracy, ability to listen its customers’ needs and its innovative drive in the design and technology increasing its turnover.

For all these reasons we have been published on some important Italian newspapers. You can find here the press review.

– corriere.it, online version of Il Corriere della Sera Click here for the news
– Affari e Finanza of La Repubblica Click here for PDF La Repubblica
– Il Giorno Click here for PDF Il Giorno

The post Bruschi on important Italian newspapers appeared first on Bruschi.