Diamonds are the hardest known natural substance and are composed of pure, crystallised carbon. There are many types of diamonds such as industrial, commercial and synthetic ones.
Commercial diamonds are transparent pieces of diamond that have been cut and polished and are used for example in jewellery – the kind we all love! Synthetic diamonds are produced through chemical or physical processes in a laboratory. However, not many people realise that industrial diamonds are just as valuable as their decorative cousins.
Industrial diamonds are used as the mechanical tips of drilling bits and for cutting because of its high thermal conductivity and its material hardness. “However, the diamond reaches very high temperatures during a typical drilling experiment due to friction,” says CSIR laser researcher Bathusile Masina, “and it is believed that the high temperature leads to stress-induced damage.”
Turning up the heat
Masina is involved in studies whereby industrial diamonds are heated by a laser beam and the resulting temperature is optically measured on the surface of the diamond. The ultimate aim of this project is that “with the heating and temperature known and measurements being repeatable, we can study temperature driven defects in industrial diamonds,” Masina says. Dr Andrew Forbes, who heads mathematical optics research at the CSIR National Laser Centre and Masina’s supervisor says, “The unique nature of this research is that the diamond is heated and measured using light, thus at no stage is there physical contact with the diamond. The importance of thermally-resilient tools in application is critical to the economic viability of those applications. It is hoped that the study will reveal how industrial diamonds can be used to secure higher efficacy and a longer lifespan in thermally demanding applications.”
Twenty-eight-year-old Masina says, “This study began in 2006 when the first challenge was to set up a laser-based system with sufficiently good power stability, beam position and suitable wavelength for absorption. We chose to use a CO2 laser. We then went further and managed to demonstrate a laser heating process by raising the temperature of a diamond sample in a controlled and repeatable manner. We are now able to measure the resulting temperature on the surface of the diamond optically. Taking these studies further, we will be measuring temperatures across the entire diamond as current studies have focused on one spot at a time.”
Based on the success of Masina’s research, the CSIR National Laser Centre was able to clinch a R1,3 million research contract with Element Six; the world's leading supplier of high-quality superabrasives and industrial diamond materials, including synthetic and natural diamonds and superabrasive cubic boron nitride.
Working her way to the top
Originally from Mpumalanga, Masina’s journey to the CSIR began when after school; she went to the University of Zululand to pursue a career in physics. Already a high flier at that stage, Masina received funding from the university based on her impressive maths and physics symbols in matric.
Originally on a studentship at the CSIR from 2006, Masina received her Master’s in physics in September 2008 and is now a permanent employee. “I am really thrilled. This is a dream come true for me!”
The teetotaller is a reserved woman who likes to spend her time at home. She enjoys inspiring movies and says, “One of my favourites is the movie ‘Faith like potatoes’. As a Christian, the movie shows how with true faith in the Lord, anything is possible.” Clearly someone with a soft heart, Masina is also an ardent follower of the reality show Khumbula ekhaya (missing home), which reunites people that have lost touch with their loved ones. “Reality TV is great; it’s about what’s really going on around us. No one is acting.”
Determined to be the best that she can be, Masina says, “I want to be the best scientist in my field and also ensure that I remain an independent woman. I like nice things – I want only the best for myself.”
There is no doubt that, in Masina’s case, diamonds are indeed a girl’s best friend!
Chiara Lincoln, email: CLincoln@csir.co.za