Die and Process Design
These subjects build on the knowledge gained in Section 1 about Defects and the Fundamentals learned in Section 2.
They teach you how to ensure that production problems and rejects are designed out of the process and out of the dies.
This is essential learning for all Die Casting techicians, even if you are not directly involved in Die Design.
Introduction to Die Casting Process Design
Die Casting Process Design must be fully integrated with Product Design and Die Design to ensure that the die will produce parts to the customer’s requirements, consistently, without defects.
However, in too many Die Casting plants, this step is performed inadequately, or not at all.
This subject explains exactly what process design entails, and provides a number of case studies showing how it can be applied in practice. This is essential knowledge for all Die Casting technical and management staff.
Sponsor: Hotflo Diecasting
Feasibility and Die Layout
This subject lays out the method required to design the process, and the die, so that it will be possible to operate it in production without making rejects.
Process design always requires iteration and choices to optimise the casting properties for the particular application, but a systematic method will always lead to better outcomes.
Feasibility analysis, and calculation of all the important process parameters, are combined with practical know-how to derrive an optimised design.
The die layout incorporates all these key features and parameters and becomes the structured input to the full die design process.
Gating and Runner Design
After a die layout has been established using the methodology described in the above subject, the complete specification of the metal feed system, from the cavity to the shot sleeve can be determined. This course covers the full range of gate types, and the procedure for developing efficient, functional runners.
Die Thermal Design
Die Casting dies only function correctly when the temperature at each location is matched to its function. Some locations need to remove heat, some locations need to slow down heat loss and others need to add heat. These issues are not always fully understood by people who are modelling the die.
This subject covers the full range of issues related to die thermal design and its integration to the process parameters. The emphasis is on calculating the heat flows into and out of the die, determining appropriate temperature gradients and designing the die cooling channels to match the proposed controller.
The thermal design of the die will effect the quality, the production rate and the cost of Die Cast parts.
Venting and Vacuum Design
With the cavity full of air before the shot starts, the die and process design team has to determine the best way to either remove it, or to prevent it from reducing the properties of the casting.
The first part of this subject covers ordinary pressure venting of Die Casting dies, which rely on the pressure inside the cavity, to push the air out of the vents ahead of the advancing metal. Methods of determining the size and number of vents are described.
The second part of the subject covers the use of vacuum to extract the air out of the cavity before the cavity fills. The different types of vacuum vents are covered in detail, along with their strengths and weaknesses. The concept of 'vacuum ready' die design is introduced and explained.
No matter what type of venting is employed, calculations, rather than guesswork, lead to better decisions and appropriately sized vents and ducts.
Mechanical Die Design
A cheap die usually results in expensive castings; especially when it involves cutting corners on die features and materials.
After using your acquired knowledge to develop the optimum process design; gating, runners, thermal balance and venting system, it needs to be backed up with good mechanical die design.
This subject looks at modern Die Casting die layouts and the materials and components that can be used to create robust, reliable dies.
Die Cast Product Design
All the other technician level subjects concentrate on the Die Casting process. When you have this knowledge it can be turned around and used to influence and modify product and part design.
Only when the product design is fully consistent with the capabilities and limitations of the process, can the lowest costs and defect levels be achieved.