As die casting expanded into several industries and alloys have been introduced, more of its strategies and techniques have been developed as the process was first used to produce type for the rapidly growing printing segment. While the high pressure casting process is the most commonly used technique today, other methods are also often employed in die cast prototyping.
Single Cavity Prototype Die
If you are going to perform extensive testing, then this is likely your ideal choice from among the prototyping strategies in use today save actual die casting. The single-cavity prototype die’s main benefit is that it lets you thoroughly evaluate the end product’s vital characteristics, comprising the finish on the exposed surface of it.
With around 75 percent production dies necessitating minor or major alternations, another advantage of this process is it can make for certain design modifications possible after the first round of components is made, thereby avoiding costlier alterations down the line.
The insert of the actual die can often be employed in the last production stage too. With this process, it usually uses less time to make final dies and secondary trim tools as opposed to other prototyping strategies.
Owing to the involved cost and the amount of time it at times takes to make dies, it may not be apt if you do not have enough lead time or there are uncertainties concerning your product’s design.
Gravity Casting
This is the most popular option to make die cast prototypes, as it is less costly than the above-mentioned strategy for small quantities of product. It also does not necessitate as much lead time in relation to the aforementioned process. It comprises most plaster molding and investment casting strategies.
While it may be even more affordable, gravity casting has a few drawbacks that have to be taken into account when deciding which prototyping strategy you are going to use. As they usually have less porosity, gravity castings usually have superior fatigue strength than castings do, for example.
Die casting can yield an output with accurate dimensions, but more machining will be necessitated to achieve the exact thorough dimensions when the above-mentioned process is used. It also cannot accomplish the extremely thin wall widths, which can be produced only by means of die casting, even though the gravity casting process can yield walls having greater widths.
Plaster Mold Prototyping
Plaster mold prototyping, also referred to as the rubber plastic mold (RPM) casting process, is a gravity-based approach that works with magnesium, zinc, ZA and aluminum alloys. Using a stereolithography model, it is possible to make a product prototype in a matter of weeks. It lets you make any required changes to the geometry of a part simply and quickly. Having a cost that usually is around ten percentage of the cost for constructing a production die, RPM can be economical than other die cast prototyping strategies.
Even though plaster mold prototyping can produce components in several sizes, it is usually most suitable if your component falls in the 2-24 cubic inches range. RPM is capable of making some or up to many thousand working prototypes, which makes it a suitable method to prototype a die cast part if your required quantity is not big enough in order to justify the hard tooling cost.
It is also capable of replicating any castable geometry. While that is one of the obvious benefits of RPM, it can lead to issues as it makes designers erroneously use geometry, which can significantly increase the costs or create a metal shape that is eventually not possible to die cast.
Rapid Prototyping (RP)
Rapid prototyping is associated often with various methods, comprising stereolithography, fused deposition modeling (FDM), and laser sintering. Contingent on the geometry of a prototype, prototyping for die cast parts with one of these processes can typically yield an initial output in just 5 to 8 weeks. These strategies work with a stereolithography model to make H-13 steel dies with pressure, instead of the gravity-fed, die casting process.
As the alloys and thermal and physical properties used in the rapid prototyping process are similar to those in the production run, RP lets you perform a precise and thorough product analysis before you even invest in the making of complex and costly die casting dies. Due to the same reason, it is usually your best option if you need to make up to many thousand units while production dies are fabricated.
This process is not typically suitable for work that involves tall standing and/or thin detail on components. It is also not the best option for a project necessitating cast-in water lines.
Machining From Similar Castings
This machining process involves making prototypes from castings with a shape and size that are similar to the one you would like to have produced. If you want many small parts’ prototypes, they can be machined out of heavier areas of a big casting with this strategy.
Suitable for making gears as well as screw-machined parts, among other items, machining from similar castings is also a good option if you want substantial prototype quantities and have accesses to the automatic processes and required materials to produce them.
Machining from Sheet or Wrought
This strategy for die cast prototyping comprise machining from sheet or wrought, when you require a prototype from sheet or obtained magnesium and aluminum. When contrasted with die casting, sheet and wrought materials have superior ductility and inferior compressive yield strength, though. These materials may have a directional quality that is undesirable, caused by the extracted alloys’ or sheet’s direction.