Diamond is the hardest and one of the most versatile materials in the world. It is widely used in industry, and everything from the cars we drive to the windows in our homes have diamond-cut components.
But while industrial diamond is incredibly hard it is also very brittle and susceptible to fracture. This is a real problem in industries, such as oil and gas exploration, where down time is breathtakingly expensive.
Improving the fracture performance of diamond is not a simple matter. The materials involved are difficult to work with and while manufacturers have a certain understanding of how the microstructures involved react, they have yet to establish exactly why fractures occur and how to toughen the diamond composite to prevent them.
Element Six is one of the world’s largest producers of synthetic diamonds and the company has a major interest in solving this problem. The company has been working on possible solutions with UCD Earth Institute’s Professor Alojz Ivankovic based in the School of Mechanical and Materials Engineering since 2006.
“We have our own research and innovation centres in Element Six but commercially it would be impossible to undertake all of the research required ourselves,” explains Dr. Wayne Leahy, applications manager, Element Six. “What we are looking for is a step change in the performance of the material. This is much more difficult to do with diamond than with steel for example where a much bigger R&D effort has always been focused. By comparison there has been relatively little work done on diamonds.
“Working with Professor Ivankovic has given us access to in-depth materials expertise and to people who can focus on the problem in great detail. It has been painstaking work, and before they could even start trying to understand how the materials behave, they had to design and build all of the equipment required to test them.
“They are using numerical models to predict the initiation, propagation and direction of cracks within super hard materials as a function of temperature and loading rate. To do this they are generating data that allows them to model and ultimately predict the fracture process under in-service conditions,”
Professor Alojz Ivankovic is an expert in the field of polymers, adhesives and composites. He is also the founder and head of Ireland’s only adhesives research group, the Centre for Adhesion & Adhesives, which is based at UCD and currently comprises 20 members.
“Industrial diamonds are about four times stronger than steel but extremely brittle so if you get a crack it just goes bang, like a glass,” he says. To understand why, we needed to look at their composition at a micro level where you can literally see the individual grains and the binder that holds them together. We are trying to see what makes the material behave the way it does and how to change its composition to make it tougher and less brittle. We have done some really good work on this and there is one patent filed and more in progress.
The current partnership with Element Six is expected to reach fruition in about 18 months time and Wayne Leahy says Element Six will be “exploring mechanisms to continue the relationship into the future.”