Additive Manufacturing of Boron Carbide by Direct-Ink Write (DIW)
Abstract
Direct-ink writing (DIW) is an additive manufacturing method that enables on-demand printing of materials into multiscale complex structures for rapid prototyping and near-net-shape manufacturing. One of the challenges of using DIW for creating ceramic green bodies is to optimize the rheological properties of the ceramic-filled suspensions or inks to ensure stable flow within the printer apparatus, minimal distortion of the printed body due to gravity (referred to as slumping), and minimal defects. The purpose of this research is to develop boron carbide (B4C) suspensions with optimal rheological properties suitable for DIW, as well as to understand the effect of the process on the bulk mechanical properties of the resulting printed and densified body. The effects of B4C content, methylcellulose binder variation, and binder content on the rheological properties of B4C suspensions were tested on a rotational rheometer to determine viscosity as a function of shear stress, as well as yield stress values, in an effort to identify an optimal suspension composition for printing. Subsequently, printed green bodies underwent a binder burnout step to remove the organic binder, and then were consolidated to high density via pressureless sintering. Microstructure and Knoop hardness were characterized. Theoretical densities as high 94.35 and Knoop hardness values of 19.24 GPa were achieved in the samples.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 2020
- Accession Number
- AD1120132
Entities
People
- Brennan Gray
- Jerry C LaSalvia
- Joshua Pelz
- Kris Behler
- Lionel Vargas-gonzalez
- Nicholas Ku
Organizations
- United States Army Research Laboratory