How to prevent cavitation?

In the molding of articles by means of zamak die casting, considerable difficulties can arise in achieving the surface quality of the casting to meet the customer’s aesthetic requirements.
In order to achieve a good surface quality of the die casting, i.e., without marbling, it is necessary for the liquid metal to reach all areas of the impression as quickly as possible and without yielding temperature. Hence the need for high pressures and high flow velocities in the filling phase.
High pressures give rise to the phenomenon called “water hammer” at the end of the filling phase, while high velocities generate flow turbulence, both of which are crucial factors in the occurrence of cavitation.
We have found in our experience that using liquid zamak injection speeds below 60 m/s significantly reduces the occurrence of the phenomenon in the mold surface – an important fact to consider when designing the mold and the process.

The use of simulation programmes to fight cavitation

A very useful tool used daily in Bruschi’s engineering area is simulation software.
With these programmes, the engineering team can simulate the filling of the product in order to design casting and vent channels capable of achieving the quality required by our customers without, however, causing premature deterioration of the mold.
During the realisation of projects, from the design phase to the production phase, with the simulation software it is possible to prevent all possible defects on the mold. In this way, Bruschi can to save time by predicting possible problems, achieving customer goals in the best possible way.
These simulations are of such importance that they are also taken into great consideration during the bidding phase to the customer, as they prove essential in anticipating any eventuality.

Conclusion

The aim of engineering is to solve the cavitation problem by studying the behavior of the fluid inside the molds on a daily basis. These evaluations are carried out using simulation software, with which Bruschi can visualise parameters such as flow velocity, pressure inside the mould and filling temperature of customer products.
Considering that each product has a unique geometry, different issues and new daily challenges arise and are addressed to ensure quality products for the Bruschi team and its customers.

The post The phenomenon of cavitation appeared first on Bruschi.

On the subject of mechanical strength, and more in detail, breaking load, in this post, we will briefly define the function of rupture tests in the structural quality control of zinc die castings during production. This article will also describe the instrument used to perform these tests to ensure compliance with the specifications of the component and some case studies related to the main topic.

Ultimate tensile stress: breaking strength test of a part or assembly

As anticipated, the ultimate tensile stress is the force that must be applied to a component to cause yielding and/or rupture and is measured in mega-pascals, indicated by the symbol MPa, which is the primary unit of pressure measurement, that is, of the force on the unit of surface.

In order to proceed with this test, the force is applied at a point of the piece predetermined and agreed with the customer to observe the load necessary to cause its breakage or yielding. In this way, it is possible to test the amount of force needed for the test piece to lose the specific mechanical properties, that is, the ability of the component to withstand external loads and, consequently, be unusable.

The execution of this process requires a specific machine for laboratory tensile/compression tests.

Therefore, this machine is extremely crucial because breaking strength tests are among the key elements for the functional verification of a finished product. Often individual zinc die-cast components are mounted in an environment or in an assembly that undergoes various stresses from the outside, and these forces, if not adequately considered and analyzed, could compromise one or more elements of the system by jeopardizing the function of the product itself. An obvious example of this concept is undoubtedly the steering group of a car that undergoes different stresses due to different drivers. The individual elements and the system must necessarily be able to perform their function without breaking even in the event of excessive forces applied by drivers with extreme driving styles. Consequently, avoiding malfunctions and ensuring the correct mechanical strength of steering components is an essential safety factor for the driver.

The ultimate tensile stress: real tests and computer simulations (FEM)

This kind of test can also be simulated within CAD (FEM) applications, but as the die casting process is known, also using vacuum technology, it does not allow the molding of parts with theoretical material density because, as a result of the volumetric shrinkage during the cooling inside the zones of the die-cast with a higher mass, microcavities are created, typically called shrinkage porosity, which could compromise the performance of the product in terms of mechanical strength. These density variations are not completely intercepted by the simulation software systems, which can be very useful in the design phase but which, in terms of production, could call into question the achievement of the required specifications due to the inaccurate results detected by the simulation program. For this reason, it is recommended to use simulation programs to define an idea of reality, a production guideline, and then, directly in the foundry, instead proceed with sample checks during the molding and verify in detail every single aspect related to mechanical strength.

Having constant real-time control over the production, cyclically checking on a sample basis, is therefore essential to verify if the production complies with the customer’s specifications. Thus, the advantage of using these control instruments directly in production involves continuous control and the ability to act in real-time to avoid any line interruptions.

In conclusion

As we have briefly observed before, the tests in production of the ultimate tensile stress do not replace the simulations, but they place side by side with different objectives. These are critical, periodic tests to ensure a reliable and specific process during production.

The post Mechanical strength: Breaking load test for zinc alloy components appeared first on Bruschi.

In this blog post, the goal is to imagine the future trends and scenarios of this process, since modern die casting has embarked on a decisive path of evolution compared to a few decades ago.
Speaking of the zinc die-casting of tomorrow, one cannot ignore the opportunities offered by simulation software.

Numerical simulation in zinc die casting

The numerical simulation of all processes allows adding value to the die casting activity because it allows reducing the time to market, optimizing the testing and verification phase and thus obtaining significant cost savings.

Numerical simulations are normally already considered for the entire filling process (see blog post: “Simulation for HPDC: scrap reduction case study“), but their use could be extended more and more to the general study of the behaviour of the die-cast object during the withdrawal phase or in the detection of any internal tensions, up to analyzing any possible anomaly in its structure and surface.

In this way, the approach to die casting becomes much more structured, moving from empirical criteria (or “trial learn”) to data-driven methodologies, capable of allowing cost and resource savings and making more informed decisions.

Furthermore, process and product simulations can serve as a database to lead zinc die casting to the discovery of new application sectors. In Bruschi, for example, simulations on thin thicknesses have given useful results for different fields of use and also in the automotive field, thanks to the simulation activity, new zinc components have been created, which perhaps without this type of analysis would not be never born.

The impact of technology on new die casting processes

Even at the process level, zinc die casting has important innovations in store, especially in Bruschi, and all are related to the contribution of technology to operational needs.

To overcome the cavitation problem, for example, certain analyzes are currently being carried out to minimize its impact, but the use of fluid-dynamics simulations is currently being studied, again through software, in order to be able to modify the feeding channel and the flow system at the origin to prevent this phenomenon from damaging the mould.

With reference to the new die-casting techniques, on the other hand, the attempt to apply the hot runner injection process, typically used in plastic moulding, to the zinc alloy is under consideration. This technique would make it possible to avoid the generation of the so-called “sprue”, reducing the costs in the management of the process connected to its subsequent elimination. The amount of heat saved by the absence of sprue to eliminate would also bring with it important consequences from a green perspective such as the production of less CO2 and therefore greater respect for the environment.

Also as regards the machines, technological progress allows to have more and more sophisticated systems for the control of the main parameters of the die-casting process, also giving the possibility to deepen the correlations between those in input (speed, pressures and characteristics of the injection profile ) with the outgoing ones (weight, burrs, surface quality), through the aid of statistical process analysis software.

Finally, we point out the studies conducted for the production of new sustainable zinc alloys, which are made exclusively through the treatment and recycling of new zamak scrap deriving from the die-casting process. This type of product allows you to embrace the themes of the circular economy, zero waste and recycling which, until a few decades ago, seemed utopia, when compared to the world of foundries. For further information on this topic, we recommend that you contact Bruschi by filling out the form at the link: https://www.bruschitech.com/contact-us-bruschi.

The advantages of zinc die casting

The advantages of zinc die casting, compared to the use of other materials such as aluminium, are numerous.

The first advantage is the greater ease of management of the final surface treatment (chrome plating, painting…). This plus linked to the use of zinc is very useful for all those applications that must meet both aesthetic and functional requirements (for example, resistance to corrosion) and is increasingly in demand on the market.

In addition, zinc die casting has a lower process cost because the zinc alloy mould lasts up to five times that of aluminium, which deteriorates much more quickly as a result of the higher melting temperature (650°C than aluminium against about 400°C of the zamak).

Then, the cycle time of the process is much faster because zinc can be treated in a hot chamber, while aluminium can only be treated in a cold chamber. We refer to the blog post “Zinc Die Casting: A Look into the Future” for the technical explanation of the difference between the two processes. What should be emphasized here is that the hot chamber process, which has always been used in Bruschi for the production of zinc alloy components, allows for greater speed in the production process and an important reduction in mechanical processing subsequent to the die-casting phase.

In conclusion: the future of the zinc die casting market

Despite the current economic situation, the die casting market is showing some encouraging trends. From today to 2026, estimates speak of a global increase of 6%, to which the zamak market also seems to comply.

Surely the technological progress that zinc die casting is undergoing and that passes, as we have said, to the ever-increasing use of software and simulation technology, can help to shift the interest of those potential customers who usually turn to the plastic or aluminium market to the zamak market.

Everything lies in continuous innovation, which can lead to the creation of high-quality zinc alloy die-cast objects from an aesthetic and functional point of view and with an important saving from the point of view of production costs. Bruschi has the ambitious goal of being at the forefront of the die-casting market and is continuously receptive to new techniques and methodologies to be applied to everyday operations to help improve the sector.

The post What is zinc die casting? What will it be like in 2022? appeared first on Bruschi.

Productivity enhancement represents, indeed, an advantage both for the supplier and the client: on the one hand the supplier benefits from costs savings, while on the other hand the client can rely on a partner that offers quality performances in short times. Bruschi has always considered this subject a core aspect, as a matter of fact through the years Bruschi has taken several measures in order to achieve an ever-increasing process improvement.

How to reach process improvement

Process improvement can be developed through a well-defined action plan, which takes into consideration the complexity of elements that characterizes the production department. Production is indeed composed not only of machinery, but also of product design, technologies, operators and planning activities, to mention some of the most important components of this structured system. To improve the production process it is therefore crucial to have a comprehensive view of all these elements, in order to implement a strategy that is functional on multiple aspects.

As a consequence, the first step to take is the setting of the tools and of the adjustment actions that can impact on the improvement of the different stages of the production. In Bruschi the process improvement plan is composed of four central elements:

1. Automation

2. Simulation

3. Scrap reduction

4. Cycle time

1. Automation

The introduction in a production system of automated machinery equipped with state-of-the-art technologies generates relevant benefits in terms of reduced lead time, costs reduction and achievement of quality standards requested by clients. The replacement of workforce with automated systems allows, indeed, to obtain a faster process, consequently enhancing the whole lead time. In addition to that, automation leads to a reduced likelihood of error compared to manual operations. This translates into a relevant production costs reduction, which is further increased thanks to energy and material saving that automation generates. The introduction of automated machinery in the production department produces another significant advantage that allows quality control improvement, too. As a matter of fact, operators that previously dealt with manual operations on the component thanks to automation can take responsibility for other activities with a higher added-value, such as quality control.

A process improvement project of a specific component, for a client of the sector of small appliances, has obtained excellent results in terms of increased productivity and decrease of manual activities of operators. Process improvement project has been developed in order to solve a situation of misalignment between production capacity and client’s demand. Through the introduction of automated systems this gap has been narrowed, thus achieving an optimized cycle time. After several studies and researches it has been possible to apply some changes to the process, which have brought to significant benefits: an increase of 33% of production capacity and a decrease of -95% of manual activities made by operators.

For more detailed information on automation consult the post below:

• How automation helps improving the production process
• The Importance Of Automation Optimize The Production Time

2. Simulation

Simulation of the die casting process represents another essential element that impacts on process improvement: with simulation software engineers can indeed foresee material reactions inside the mold. This process is feasible thanks to a thermos-fluid dynamic analysis of the mold, known as CFD simulation (Computational Fluid Dynamics), which allows the engineer to detect potential defects, such as cold laps and hot spots, on the die cast. The simulation stage proves especially helpful to obtain an optimized mold design before starting with the production process. During this stage it is indeed possible to select the best mold design parameters to apply, so that potential defects on the piece are previously detected and, consequently, production costs and further mechanical operations are reduced.

If you are interested in simulation, here are additional posts on this topic:

• The Benefits Of Simulation In Die Casting Design
• Die Casting Simulation For Shrinkage Porosity Prediction
• How To Use Die Casting Simulation For Cost Reduction
• Hpdc Simulation For Die Casting Process Optimization
• Die Casting Simulation A Casting Process Optimization
• Hpdc Simulation Benefits For Die Casting
• Simulation For Hpdc Surface Aesthetical Quality In Automotive Case Study
• Simulation For Hpdc Shrinkage Porosity Case Study
• Simulation For Hpdc Die Maintenance And Optimization Of Set Up

3. Scrap reduction

Scrap reduction can be achieved through an accurate planning of the whole production process of a component. First of all it is necessary to carry out a product and process analysis that focuses on the causes of scrap. To identify these causes engineers must use simulation software to foresee every stage of the production, from design to finishing operations. Once again simulation proves to be an indispensable tool for zinc die casting process improvement, because it allows engineers to avoid defects and to check technical properties before starting with the component production, thus producing a consistent costs and lead time reduction. Once scrap causes have been figured out it is possible to proceed to the outlining of potential solutions to apply, identifying the most relevant steps in the production process and constantly checking them.

To know more about scrap reduction, here are extra posts on the topic:

• How To Reduce Scrap In Die Casting Process
• Simulation For HPDC Scrap Reduction Case Study

4. Cycle time

The expression cycle time defines the period of time required to produce a product. Cycle time represents a central variable in the production of a component because a reduced cycle time results in a reduced lead time, which is the period of time needed to accomplish a customer’s request in terms of supply. An optimized lead time generates an increase in the client’s satisfaction, because it allows the supplier to meet deadlines and standards demanded by the client. As a consequence, in order to guarantee a rapid and efficient service, cycle and lead time have to be enhanced to the maximum extent possible. Cycle time can be shortened paying attention to different aspects of the production process, especially to simulation stage and to technological systems of the production department. First of all, as already mentioned, it is important to simulate production and defining the best process parameters to apply for the production process. In this way potential defects will be avoided from the very beginning and, consequently, it will be possible to eliminate further mechanical operations. Another core element for cycle time shortening is the technological system of the foundry, whose technological innovation level can generate relevant time reduction during the production process. As a matter of fact, automated machines lead to optimized cycle times and to more accurate operations, discriminating factors for the achieving of performances requested by customers. Furthermore, periodical checks on machinery help understanding how cycle time can be further improved.

Check the posts below to learn more about cycle time:

• Process Optimization For Die Casting Cycle Time Reduction
• How Die Casting Cycle Time Optimization Can Help To Reduce Costs

Why process improvement is crucial for a business

Process improvement is a crucial element in the management of a business because it leads to production costs reduction and faster productive processes. With the aim of reaching these benefits it is therefore necessary to introduce automated technology and simulation software in the production process, and to optimize scrap reduction and cycle time. With the outlining of a precise process improvement plan lead time can be shortened and, as a result, client’s satisfaction will be increased.

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

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

The post Production process improvement in the die casting industry appeared first on Bruschi.

This year Bruschi has purchased new die casting machines to improve its industrial machinery in its foundry. Bruschi has always been aware of the importance of innovation and technology, the business philosophy is indeed based on three mainstays: mass-production, co-design and technology.

Die casting machines

Bruschi has purchased four new die casting machines: one of 50 tons, two of 125 tons and one of 200 tons. These industrial machinery are: Frech DAW50W, Frech DAW125W e Agrati HC200. An important investment that allowed Bruschi to further enhance its production department. The new machines are provided with specific functions, listed below:

Pieces check inside the mold

It is possible to connect the new die casting machines to a camera that allows the check of the pieces inside the mold. This results in decreasing cycle time and avoiding damages of the mold.

Pre-filling

Pre-filling function enables the movement of the injection piston up to a determined stroke with the mold open. This action reduces the air quantity inside the mold and the cycle time.

Safety system

The new industrial machinery have a safety system that protects the mold from potential damages.

Automated regulation of closing force

Automated regulation enables a more accurate control of the closing force.

Automated loading of ingots

Agrati HC200 has an automated loading system of zinc ingots. This system generates two advantages: energy saving thanks to pre-heating and reduction of workload of the operator.

Thermal deburring machine

The machine for thermal deburring is the Extrude Hone Thermal Deburring and it will be at Bruschi plant by the end of 2018. It is the first thermal deburring machine in Bruschi and it has been purchased because the presence of this machinery in the production department generates a quicker, constant and quality production. Furthermore, the machine produces an indirect advantage: reduction of non-compliance issues. As a matter of fact, components that undergo a thermal deburring process present a superior quality compared to pieces that undergo manual deburring.

Advantages of new die casting machines in the production department

This relevant investment allowed Bruschi to align itself to the performances demanded by clients: thanks to technological development of new industrial machinery production benefits from a decreased cycle time and this translates into a more efficient and rapid service. In addition to that, new safety systems of these new die casting machines also generate a decrease of production times, because they lead to a reduction of the number of actions needed for the restoration of the molds. Furthermore, the purchase of machines from different suppliers allows the company to have a wider and diversified point of view on current offer.

To always be up-to-date with news on zinc die casting and our foundry, subscribe to our blog.

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

The post Industrial machinery: Bruschi’s new die casting machines appeared first on Bruschi.