Additive Manufactured Copper Materials for Launcher Engines

Additive Manufactured Copper Materials for Launcher Engines

ESA Case Studies Additive Manufactured Copper Materials for Launcher Engines

Primary Contact: Dr. Hoda Amel, Advanced Research Engineer – Additive Manufacturing, hoda.amel@the-mtc.org

Start Date: February 2018

Anticipated Completion Date: July 2019

Collaborators

  • The Manufacturing Technology Centre (MTC)
  • Fraunhofer Institute of Laser Technology (ILT)

This project is a feasibility study for manufacturing of Thrust Chamber Assembly (TCA) liners, which are commonly produced with copper alloys, using additive manufacturing (AM). Liquid propulsion for launchers often requires rather complex TCAs, commonly produced of copper (Cu) alloys and reinforced with high-strength materials. Production of these components through traditional manufacturing techniques is considered challenging and incurs significantly high cost and lead time, a case study where AM technologies can provide great added value. The specific AM technology being used for this work is laser powder bed fusion (LPBF) using Cu.

In this study, a new design for the TCA liner will be proposed by ESA and MTC. The design work will consist of design for improved performance, taking advantage of the geometric design freedom that AM provides, whilst also considering design for manufacture, with the geometry being constrained by the design rules of the LPBF process, such as minimum feature size / wall thickness, overhangs, surface roughness, and material properties. Finite element (FE) modelling techniques will be used to analyse the structural and thermal performance of the TCA liner. The material property data used in the analysis model will be based on the data extracted from mechanical testing of samples built by the same process as the TCA liner.

Fraunhofer ILT will use LPBF to build samples, cut-outs and sub-scaled TCA liners out of Cu alloys (example shown in Figure 6) to investigate the applicability of such processes for liquid launcher propulsion systems. The LPBF system to be used in this work is a modified Trumpf TrumaForm system at ILT, which is suited to the needs of Cu processing. Process parameters for Cu alloys have to be optimised due to its high thermal conductivity and low absorptivity (depending on laser wavelength used). After selection of the optimised process parameters, test samples will be manufactured for tensile, low cycle fatigue and creep testing. These samples will be tested at room and elevated temperatures and the results will be fed into the design work. In order to assess manufacturability of crucial features including cooling channels and overhangs, cut out sections, a TCA liner downscaled to 75 mm in height and a complete sub-scaled TCA liner with the height of 200 mm will be manufactured.

Figure 1 - Example of LPBF process for Cu alloys at Fraunhofer ILT