In cutting discs used heavily in the stone sector, the periodic forces acting during cutting generate an inhomogeneous stress field which can become problematic, particularly if the temperature rises. Our research seeks to solve this problem through the incorporation of active NiTi shape memory alloy inserts, in order to counteract stress concentrations at elevated temperature. When pressed into the steel disc, a stress-induced phase transformation forces the NiTi insert into a mixture of austenite and martensite phases (blue curve). During heating, the insert tends to elongate as it transforms back to the parent austenite form (red curve). The constrained insert therefore exerts significant stress on the steel (black arrow), modifying the stresses experienced in service. We used the unique capabilities of Engin-X to find out how exactly the stress redistributes around a NiTi insert in-situ during mechanical and thermal loading. The results will be used alongside models to develop innovative solutions for improved performance and lifetimes of cutting discs.
B Malard, P vSittner, J Pilch, V Davydov (Institute of Physics, Academy of Sciences of the Czech Republic), EC Oliver (ISIS)
Contact: Dr P vSittner, email@example.com
Research date: December 2008
P vSittner et. al., Mater. Trans, JIM, 43 (2002) 984