1. Tungsten Carbide-Cobalt Nanomaterial Research and Industry Application
Co-Instructors: Dr. Leon Shaw, Dr. Robert Anderson
Students: Ryan Eggert, Bader Jarai, Andrew Kang, Fawzan Khan, Nicholas Ma, Anas Rasoul, Tyler Seppala, Xiajing Wang
Our goal is to create tungsten carbide-cobalt (WC/Co)
nanomaterial cutting tool materials which are tougher and
harder than the industrial standard
XRD pattern of
ball milled powder
mixture, indicating
the presence of WO3
and CoWO4.
After reduction and
carburization, all WO3
and CoWO4 have
been converted
to pure WC/Co.
A unique feature of our IMTA-processed powder is the long and thin WC platelets.
The thin thickness offers high hardness while the long platelets simultaneously
provide high fracture toughness.
IMTA-Processed Equiaxed WC
WC Platelets
A diamond indentation reveals that IMTA-processed WC/Co has much
higher crack growth resistance than commercially produced WC/Co.
Sintered WC-18wt.% Co with WC Sintered WC-5wt.% Co purchased
platelet microstructure produced from a commercial manufacturer
from nano-WC/Co powder
The high crack growth
resistance of our WC/Co
is due to its thin WC
platelet microstructure,
creating a torturous path
for the crack to propagate.
While commercial WC/Co has failed to achieve high hardness and
high toughness simultaneously, our IMTA-processed WC/Co has
achieved both qualities.
WC/Co cutting tools make up 98%
of all hardmetal components,
including cutting tools, drill bits,
and wear-resistance components.
For these tools, high hardness and
high toughness is required.
In the industry, WC/Co cutting tools
have not been able to achieve both qualities simultaneously.
Using the IMTA (Integrated Mechanical and Thermal Activation)
process, we are able to achieve both high hardness and high
toughness.
The Steps of the IMTA Process
Synthesis
• High energy ball milling of CO3O4 and WO3 powder mixtures
at room temperature for ~2 hours
• Reduction of the powder at ~700°C for 1 to 2 hours
• Carburization of the powder at 1000°C for 1 to 3 hours
Fabrication
• Sintering to covert nano-WC/Co powder to cutting tool
inserts
Benefits of IMTA
• Two Steps vs. Conventional Six Steps
• Lower Temperatures (1000°C vs. 1400-1600°C)
• Faster Process (One Day vs. Multiple Days)
5
10
15
20
25
30
6 8 10 12 14 16 18 20 22
Vickers Hardness, GPa
Toughness,MPa.m
1/2
What Is Our Goal?
Why Is Our Research Important?
Our Solution – IMTA Process
X-ray Diffraction (XRD) Analysis of IMTA-Processed
WC/Co Powder
Microstructure of IMTA-Processed Platelets vs.
Commercially Produced Platelets
High Crack Growth Resistance
Results