0

Full Content is available to subscribers

Subscribe/Learn More  >

Processing and Analysis of Ceramic Mesoscale Combustors Fabricated by Co-Extrusion

[+] Author Affiliations
Khurshida Sharmin, Ingmar Schoegl

Louisiana State University, Baton Rouge, LA

Paper No. IMECE2013-64866, pp. V02AT02A052; 7 pages
doi:10.1115/IMECE2013-64866
From:
  • ASME 2013 International Mechanical Engineering Congress and Exposition
  • Volume 2A: Advanced Manufacturing
  • San Diego, California, USA, November 15–21, 2013
  • Conference Sponsors: ASME
  • ISBN: 978-0-7918-5618-5
  • Copyright © 2013 by ASME

abstract

In this work, millimeter-scale tubular combustion channels were fabricated from ceramic precursor materials. Co-extrusion of structured feedrods holds promise for the development of multi-layered, functionally graded and/or textured combustor walls, but requires a polymer binder that is difficult to remove before structures can be sintered to full density. In conventional thermal debinding, cracking is a major issue, where crack formation is attributed to a lack of pore space for outgassing of pyrolysis products. The main focus of this study is to validate a manufacturing process that uses a combination of solvent de-binding and thermal debinding, which is applied to a simple combustor geometry. Alumina powder was batched with a mixture of polyethylene butyl-acrylate (PEBA) and polyethylene glycol (PEG) in a torque rheometer. A 19mm feedrod, consisting of a carbon-black/binder mixture as core, and a surrounding ceramic/binder mixture forming the wall, was extruded through a 5.84 mm die. The binder removal involves two processing steps, where the PEG content was removed by solvent extraction (SE) to initiate pore formation, after which thermal de-binding by pyrolysis removes the remaining binder and carbon-black. Solvent extraction was performed in water at three different temperatures for various times. The 1:1 mixture of PEG:PEBA showed the highest PEG removal of 80wt% for 6 hrs extraction. The thermal de-binding cycle was designed based on thermo-gravimetric analysis (TGA) and successfully performed with a ramping rate of 1.25°C/min to 1000°C without any crack formation. After de-binding, samples were sintered at 1600°C for 1 hr. SEM analysis showed some void spaces in the solvent extracted samples but confirmed that solvent extraction followed by thermal de-binding yielded the best results. The viability of sintered ceramic tubes was tested for conditions typical for thermal cycling in a combustion environment.

Copyright © 2013 by ASME

Figures

Tables

Interactive Graphics

Video

Country-Specific Mortality and Growth Failure in Infancy and Yound Children and Association With Material Stature

Use interactive graphics and maps to view and sort country-specific infant and early dhildhood mortality and growth failure data and their association with maternal

NOTE:
Citing articles are presented as examples only. In non-demo SCM6 implementation, integration with CrossRef’s "Cited By" API will populate this tab (http://www.crossref.org/citedby.html).

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In