Design Issues for Microformed Sheet Metal Components

Abstract

With the miniaturization of sheet metal working, a new method for designing the component and the associated manufacturing process must be sought. Standard methods for tolerances synthesis, formability study and part inspection are inadequate when applied to under millimeter components. The dimensional and geometrical tolerances are often of the same order of magnitude as the part dimensions, making harder the realization of functional assemblies. Micro-formed parts exhibit a peculiar behavior during the forming steps due to the so-called size effects. Furthermore, the inspection of micro-parts requires statistical approach and special instrumentation.

The paper analyses the performance of the microforming process by means of Finite Element simulation of the influence of size effects on the expected results. This is the basis for the setting or framing of design methodologies able to control surface topography errors by means of Geometrical Dimensioning and Tolerancing and statistical analysis tools. The paper highlights that simultaneous engineering techniques, already suggested for the development of standard components, are indispensable with micro-dimensional forming applications.