Reaction-bonding of aluminum oxide processed by binder jetting. (May 2019)

• Record Type: Journal Article
• Authors: Solis, Daphene M.; Silva, Antonio V.; Volpato, Neri; Berti, Lucas F.
• Is Part Of: Journal of manufacturing processes. Volume 41(2019)
• Page Start: 267
• Page End: 272
• Publication Date: 2019-05
• Subjects: Additive manufacturing -- Binder jetting -- Reaction-bonded -- Aluminum oxide -- Aluminum; Production management -- Data processing -- Periodicals; Manufacturing processes -- Periodicals; Procestechnologie; Productietechniek; Production -- Gestion -- Informatique -- Périodiques; Fabrication -- Périodiques; Manufacturing processes; Production management -- Data processing; Periodicals; 670.5
• DOI: 10.1016/j.jmapro.2019.04.008
• Languages: English
• ISSNs: 1526-6125

Abstract

Highlights: The binder jetting principle combined with reaction bonding aluminium oxide technique allows to generates near net shape ceramic samples. The percentage of aluminum in the analyzed powder formulations do not affect density or apparent porosity. The percentage of aluminum in the analyzed powder formulations affect flexural strength and shrinkage. The high porosity generated during the manufacturing process improve the oxygen diffusion, allowing an effective aluminium oxidation. Abstract: The combination of additive manufacturing based on the binder jetting and reaction-bonding aluminum oxide (RBAO) techniques can produce fully ceramic specimens near net shape. This study developed powder formulations composed of stearic acid coated aluminum (Al) powder and dextrin coated aluminum oxide (Al2 O3 ) powder, in order to be processed via binder jetting, and post-processed via RBAO. The coated powders were mixed with different volume ratios of Al to Al2 O3 . After the printing process, the specimens were heat treated from room temperature to 1200 °C, in an oxidative atmosphere. Increasing Al volume ratio from 0.25 to 0.50 generated a significant flexural strength improvement, reaching about 20%. This increase had no influence on apparent porosity or density, which averaged at 64% and 1.35 g cm −3, respectively. A complex geometry model was built to prove the feasibility of producing sophisticated parts. As expected, post-RBAO parts shrinkage was nearly zero, proving the feasibility of the additive manufacturing, by binder jetting, and RBAO combination.