Shyam Bahadur and Alan Russell, Iowa State University, Ames, IA, USA
The objective of this work is to study the abrasion behavior of ultra-hard boride materials. The abrasion resistance of the materials will be studied by single point abrasion at low speeds and multiple point abrasion at high speeds, and the effects of strain rate, temperature and oxidation effects will be analyzed. The mechanisms of material removal will be studied by electron microscopy of the abraded surfaces as well as the deformation in the substrate. As a part of the effort, it is intended to synthesize a new material AlCrB14, as a modified version of AlMgB14, and modify its grain structure and mechanical properties, including fracture toughness, by sub-micron size TiB2 additions for excellent abrasion resistance. The synthesis of the new material addresses to the environmental concerns involved in the processing of AlMgB14 boride because of the volatile and reactive Mg. If the processing is successful, super hard materials with hardness equal to or greater than that of cubic boron nitride (CBN) are expected to be obtained. If the processing of the new material is unsuccessful, the abrasion studies will be performed on AlMgB14 whose hardness is close to that of CBN. The materials will be characterized in terms of hardness, fracture toughness, and flexure properties and these will be related to the abrasion resistance. The project is cross-disciplinary involving materials development and further modification for enhanced tribological performance. The economic benefits of the newly developed materials for potential applications in earth moving, mining, rock drilling and other tool materials are tremendous.
