An investigation into the characteristics of materials and processes, for the production of accurate direct parts and tools using 3D rapid prototyping technologies

摘要

The work reported here reflects the fundamental research undertaken by the author into the technologies of Rapid Prototyping, Rapid Manufacturing and Rapid Tooling. This research was undertaken over 4 years, in a period when these technologies were experiencing huge change, through innovation and development, to produce viable and reliable industrial processes. The research presented here deals with the two low cost, high speed Rapid Prototyping manufacturing processes. The first technology produces concept models for verifying design intent in the early stages of the product development cycle — referred to as the Z-Corps 3D Printing, 3DP process. The second technology investigated was the EnvisionTec 3D Digital Light Manufacturing, DLM process. This is machine capable of producing final parts in real engineering materials. In both cases the default manufacturing settings and materials were evaluated for accuracy, finish and material properties and an experimental test methodology was developed. Each process was then optimised utilising Taguchi techniques and applied to industrial projects. Finite Element Analysis (FEA), has been used to predict best build orientation for these non-isotropic materials. This work investigating the Z-Corps 3D printing process has improved the accuracy by 2%, part strength by 25% using new infiltrates and has been applied to both production of polymer injection mould tool inserts and electrode manufacture. The EnvisionTec Digital Light Manufacturing build parameters have been optimised and characterised for accuracy, hardness, part strength, surface finish. The application of FEA analysis using Non-isotropic properties has been shown to improve product performance by 14% and the optimised process has been applied to Rapid Tooling applications. In all twelve case studies are presented here, several of which have been turned into successful commercial products, and for one case over 1 million products have been sold.