1. Preparation of Ceramic Suspension
Additive Manufacturing of Metamaterial Structures
Avishek Ghosh
Supervisors: Prof. B. Vaidhyanathan and Dr. D. Cadman
Advanced Ceramics Research Group, Loughborough University, UK
Summary
This research project will asses the feasibility of introducing novel metamaterial structures (nano-micron-meso-macro scale) and the integration of an additive manufacturing process into electronic component design. This interdisciplinary research work will combine the use of materials synthesis, characterisation and novel field assisted processing methodologies to develop customized 3D printing and sintering techniques capable of fabricating hybrid ceramic/metal/polymer metamaterials structures for high frequency applications in electronics, communication, defence etc.
Objectives
 Synthesis and processing of nano electroceramic powders for ink formulations.
 Optimisation of inks through rheology testing for 3D printability.
 Evaluate additive manufacturing capabilities of nano dielectric suspensions.
 Multi-material 3D printing of dielectrics and metals for high frequency applications.
 Characterisation of 3D printed structures and performance evaluation.
Methodology
A methodical approach is applied for nano-BT ink formulations as a case study. The processes delivered high solids content ceramic suspensions by adding suitable dispersants with satisfactory properties in terms of viscosity, density and printability.
Use of reasonable amount of Dispersant.
Thermo mechanical Treatment.
Preparation of Ceramic Suspension
Rheology test
Conventional and slow Sintering method.
Densification through evaporation of water and binder particles.
Sintering
Study and measure flow properties i.e. Viscosity, Shear rate, printability.
nano-BT Suspension
Materials
Quantity
Barium Titanate
82 wt %
Deionized water
13 wt %
Darvan 821
5 wt %
Factors affecting nano-BT suspension printability and performance,
►Homogeneous distribution of
particles.
►High solids content with less
agglomeration.
►Satisfactory level of viscosity for
3D printing process.
► Satisfactory level of viscosity as a function of shear rate, suitable for 3D printing.
► nano-BT powder dispersed well in the presence of Darvan C dispersant.
Results
Optical Microscopy
Sintered 3D printed part
Sintering parameters
Max temp
1350 ⁰C
Heating rate
5 ⁰C/min
Cooling rate
10 ⁰C/min
3D Printing Parameters
Flow rate
100 to 130 L /sec
Nozzle Diameter
400 to 600 microns
3D Printing Conventional Sintering
Future Work
Therefore, the present study is aimed to i) improvise printing performance and quality, ii) Develop dual nozzle and print multi-material component with various graded pores, iii) analyse printed parts in terms of high frequency response.
Dual Nozzle design
Ceramic Ink
Software and Hardware
Repetier Controller
Arduino Firmware
Metal Ink
Final component