Post-processing

In this chapter we will discuss quality aspects with respect to post-processing for Additive Manufacturing. A short summary with external links is given. The full document can be downloaded HERE.

amvaluechainpostprocess Applications: regulations and requirements Design Machine Material Process Metrology & Maintenance Quality Management System for AM

Keywords:Thermodynamic post processing steps, mechanical post processing steps

Introduction

Necessary post processing steps must be considered during design of the AM manufacturing of a product, thereby taking into account the material which is used (cobalt chrome or titanium) and the technology (EBM or SLM) and machine which is used to manufacture the product. Not all the product requirements can be met by these production steps. Post processing is therefore essential to compensate for undesired part properties which have been build up during the manufacturing process.

Procedures for post processing can be subdivided in two segments. As a first segment thermodynamic post processing, comprises heating procedures and determines the microstructure, residual stresses and porosity of the AM manufactured product. The second segment is mechanical post processing, which compensates for surface properties and dimensional tolerances of the product.

This chapter primarily addresses the standard operating procedure for post-processing of Ti6Al4V AM parts.

Content

  1. Thermodynamic post processing steps
  2. Mechanical post processing steps
  3. Cobalt chrome
  4. Standards for post processing

1. Thermodynamic post processing steps

Thermodynamic post processing steps comprise heat treatments of the AM manufactured product. The following heat treatments are required for Ti6Al4V components made by AM:

Insidemetaladditivemanufacturing.com on HIPing

2. Mechanical post processing steps

  • Sandblasting
  • Remove part from substrate
  • The removal of powder
  • Support removal
  • Mechanical machining
  • Machinal surface finishing
  • Non-mechanical machining for Surface finish improvement

3. Cobalt chrome

More information regarding cobalt chrome post processing can be found here.

4. Standards for post processing

Often, requirements of materials and the end product are described in detail in standards, which can either be application specific or industry specific (i.e. dental, aerospace, medical).


As an example, section 12 and 13 of ASTM F2924 describe thermal and HIP post processing steps. Also, generic Ti64 standards are relevant for post processing, by defining the required material properties.


Furthermore, material suppliers generally provide guidelines for post processing that specific material.