Densification and Geometrical Assessments of Alumina Parts Produced Through Indirect Selective Laser Sintering of Alumina-Polystyrene Composite Powder

Jan Deckers,Ludwig Cardon,Jean-Pierre Kruth,Khuram Shahzad,Jef Vleugels

doi:10.5545/sv-jme.2013.998

Abstract

A powder metallurgy (PM) process to fabricate alumina parts through indirect selective laser sintering (SLS®) of alumina-polystyrene composite powder particles is presented. The PM process includes powder production through dispersion polymerisation, SLS®, debinding and solidstate sintering. Dimensional changes, which occur during the debinding and solid-state sintering, are assessed. Warm isostatic pressing (WIP) and both pressureless and pressure infiltration are introduced as extra steps of the PM process chain. The influence of WIP and the infiltration steps on the changes in density, geometry and microstructure during the PM process are investigated.

Highlights

0.1 AM of PolystyrenePolystyrene is one of the most popular polymers used in additive manufacturing (AM) technology
It has been used to demonstrate newly developed AM technologies, such as layered electro-photographic printing by Cormier et al [1], selective inhibition sintering by Khoshnevis et al [2] or various kinds of laminated object manufacturing (LOM) technologies (Brooks and Aitchison [3], de Smit and Broek [4], or Mahale et al [5])
The presented powder production route led to a composite powder with 39 wt% polystyrene

Summary

Introduction

0.1 AM of PolystyrenePolystyrene is one of the most popular polymers used in additive manufacturing (AM) technology. Polystyrene has been used to demonstrate that AM technologies can improve the investment-casting (IC) process by reducing tooling costs and production lead-times (Cheah et al [6]). As illustrated by Cheah et al [6], two main application areas exist: 1) AM technology can be applied to produce inserts to injection mould polystyrene parts, as illustrated by Kinsella et al [7]; 2) AM technologies can be applied to produce polystyrene IC patterns. These patterns can be master patterns (e.g. for silicone rubber moulding), but are mostly sacrificial patterns

Results

Discussion

Conclusion