Influence of thermal sintering protocol on materials properties of tungsten carbide alloy (WC-17%Co) components by binder jet printing

• Main Author: Low, Tammy Chien-Yu
• Other Authors: Tan Kwan Wee
• Format: Final Year Project
• Language: English
• Published: Nanyang Technological University 2020
• Subjects: Engineering::Materials
• Online Access: https://hdl.handle.net/10356/138629
• Institution: Nanyang Technological University

Binder jet is a type of 3D printing technique that operates at low temperature and print objects to its near net shape. It enables subsequent post shaping process to be omitted, possibly cutting down on processing steps and cost. Here we report the processing and associated mechanical properties of tungsten-carbide-cobalt alloy (WC-17%Co) components by 3D binder jet printing. First, the WC-17%Co powder were printed as green samples in the form of cuboid shape by binder jet printing. The green samples were then sintered in vacuum at 1350°C and 1400°C for a duration of 2-3 hours. A key finding is immersing binder jet printed WC-17%Co components in a sand bed for thermal sintering enabled 3D shape control and uniform shrinkage. WC-17%Co components sintered above 1400 °C had the highest density and lowest porosity of 13.13 g/cm3 and ~0.17%, respectively, as well as the highest hardness measurement of 1381 HV10. We conducted preliminary finite-element analytical simulations to correlate and understand deformation mechanisms in the ceramic WC under compression. Our results suggest improvements in thermal sintering can enable shape control and improvement of associated mechanical properties in 3D binder jet printed metal components for advanced applications such as tool inserts.