Only rarely is it appropriate to make prototype castings by the pressure diecasting process. Usually the cost will be too high and the lead-time will be too long. However when the proposed diecasting’s performance can be adequately predicted by analytical techniques such as finite element analysis, the assurance of product success may be high enough to justify fabricating prototypes from production tooling.
No other metal forming process can precisely reproduce the combination of precision and mechanical properties achieved with zinc alloys by the pressure diecasting manufacturing route. In consequence it is quite usual to produce prototypes from a different zinc alloy than that intended for production and by a different manufacturing method.
The following factors must be considered when selecting an alternate process and alloy for prototyping a die-cast product.
- Details of the product application, such as operating environment and method of attachment
- Performance specifications for the end product
- Test schedule for the prototypes
- Number of prototypes required
- Cost and delivery schedule for the prototypes
- Characteristics of the end product that must be matched by the prototype, including:
- Shape and fit
- Appearance, usually surface finish and treatment
- Chemical properties, which affect atmospheric corrosion, galvanic corrosion and toxicity
- Assembly requirements
- Physical properties, such as density, electrical conductivity and thermal conductivity
- Mechanical properties, such as tensile strength, ductility, hardness, wear resistance, and impact strength