Enhancing the Capillary Force of Binder-Jetting Printing Ti6Al4V and Mechanical Properties under High Temperature Sintering by Mixing Fine Powder

Abstract

Binder jet 3D printing (BJ3DP) is an additive manufacturing technology that selectively deposits binder on powder to form a three-dimensional green body followed by sintering process. The low strength of green body and metallurgical issues limit the manufacture of Ti6Al4V parts with high-performance and that are lightweight. In this study, thermal-bubble inkjet technology was used to print Ti6Al4V parts via jetting low-concentration in-situ polymer binders. In addition, a method for mixing fine powder was used to enhance the capillary force of the powder bed and mechanical properties of the parts. The results show that the capillary force was enhanced from 8.35 kPa for pure powder to 16.27 kPa for mixed powder by mixing fine powder. The compression strength of green body was enhanced from 1.5 MPa to 3.21 MPa. After sintering, the sample with mixed powder sintered at 1420 °C for 2 h had achieved a maximum density of 95.2%, microhardness of 316 HV, and yield stress of 589 MPa. The relative density of 95.2% of Ti6Al4V parts fabricated by BJ3DP technology in our study is significantly higher than the value reported in the existing literature. Finally, the porous structure with a size of 550 μm was fabricated. Results presented demonstrate that BJ3DP can produce Ti6Al4V parts with excellent properties.

Analysis of the Flatness Form Error in Binder Jetting Process as Affected by the Inclination Angle

“…Tang et al experimentally verified the different wettability of the binder on two different particle size distributions. The particle size determining a higher powder bed density produces a slight increase in the contact angle and a dramatic increase in infiltration time [34]. Therefore, powders in a dense arrangement (high powder bed density) determine a high saturation level, while low packed powders (low powder bed density), are related to a lower saturation level.…”

A general fruit acid chelation route for eco-friendly and ambient 3D printing of metals

“…An eco-friendly chelator-based binding mechanism for BJM3DP was proposed and the feasibility of achieving an effective 3D printing system was demonstrated in this study. In the field of BJM3DPs, a few candidates for green-solvent-soluble binders have been reported so far, such as polyvinyl alcohol (PVA) 37 , 42 , 57 , polyacryl amide (PAM) 58 , polyvinyl pyrrolidone (PVP) 59 , and maltodextrin 37 , some of which were adopted from successful demonstrations in the field of ceramic BJ3DPs for biomedical applications 58 . However, the mechanical properties of the printed metal objects based on them, even with highly tough Ti−6Al−4V alloy, were mostly rather less competitive for broad applications compared to the ones based on common binder materials developed without considerations for eco-friendliness.…”

Comparative Study on Microstructure and Corrosion Resistance of Al-Si Alloy Cast from Sand Mold and Binder Jetting Mold

“…Several studies have focused on improving this process, applied to different materials. Tang et al [7] optimized the binder jetting process for inkjet printing Ti6Al4V parts with excellent properties. Mariani et al [8] demonstrated the feasibility of binder jetting technology to print WC-Co parts.…”